Earth

Earth, also known as the Earth (TV: The Christmas Invasion, AUDIO: The Beginning) and Planet Earth, (TV: World War Three, The Long Game, Bad Wolf) was a planet in the solar system whose native sapient species included the human race (TV: The End of Time) and the Silurians. (TV: Doctor Who and the Silurians) The twin planet of Mondas, it was the third planet from its sun and therefore also known as Sol III (or Sol 3), (TV: The Deadly Assassin, The Invasion of Time, Voyage of the Damned) though mainly to extraterrestrial cultures. Eventually, it was shifted across two light years by the Time Lords, and renamed Ravolox. (TV: The Mysterious Planet) In interstellar law it was also referred to as Planet C-Z-456378-D-C-D-C/42-K. (AUDIO: The Doomsday Contract) In one potential future, societal environmental irresponsibility caused the planet to degenerate into an orphan planet, and it became known as Orphan 55. (TV: Orphan 55) It had counterparts in other timelines, but these were only derivatives branching from the original, True Earth. (PROSE: Warlords of Utopia)

By the 20th century, various incarnations of the Doctor, (TV: Twice Upon a Time, Partners in Crime, The Eleventh Hour) as well as Romana (TV: City of Death) and Captain Hardaker (TV: Voyage of the Damned) referred to Earth as a "Level 5 planet".

It was a planet in which the the Doctor had a "particular interest" (TV: The War Games) in all known incarnations. (AUDIO: A Thing of Guile) It may even have been the origin of some of the Doctor's DNA. (TV: Doctor Who) Certainly, it was the planet from which the Doctor drew most of their travelling companions. It was also a planet about whose complete history the Doctor had demonstrated expertise, often knowing minutiae about it and being able to sense which points in its history and in its solar system's history were able to be altered, and which not. (TV: The Waters of Mars) The Fourth Doctor once referred to it as his "home from home", (AUDIO: The Devil's Armada) as did the First. He found that something about the planet always cheered him up. (PROSE: The Rag & Bone Man's Story) Although the Twelfth Doctor for a time claimed that the Earth wasn't his home, (TV: Kill the Moon) he later admitted that "This [was his] world too." (TV: In the Forest of the Night) Even the War Doctor maintained a special fondness for Earth and Terran culture. (AUDIO: A Thing of Guile) By the 21st century, the Doctor had become an integral part of Earth culture. (COMIC: The Mark of Terror, etc.)

It attracted many alien invasion attempts throughout its multi-billion year history. Indeed, it owed its very existence to a species that hadn't originated there. Its core was formed around either a Racnoss webstar (TV: The Runaway Bride) or a Time Lord containment shell (PROSE: Interference - Book One) which hid the caldera. (PROSE: Head of State, A Bloody (And Public) Domaine)

Still, it was not a planet that was merely ripe for invasion. Its history included long periods of time where it was a formidable player in intergalactic politics. At the height of its influence, Earth was the centre of several massive empires and confederations, and its DNA was flung to the furthest reaches of the universe. (TV: Frontier in Space, The Monster of Peladon, Utopia, The Long Game, Planet of the Ood) Earth was thought to be the homeworld of the Enemy in the War in Heaven, (PROSE: Interference - Book Two, T.memeticus: A Morphology, etc.) with some Time Lords suspecting that the thousands of alien invasions the planet endured were faked. (PROSE: The Ancestor Cell)

Location
Earth was located at galactic coordinates 58044 684884 (TV: The Pirate Planet) in Sector 8023 of the Third Quadrant. (TV: Logopolis) Being caught in a time corridor on Frontios, the Fifth Doctor commented that the TARDIS was being dragged towards "the middle of the universe" before arriving on Earth. (TV: Frontios)

It was the third planet in the solar system, (TV: The Deadly Assassin, The Invasion of Time, Last of the Time Lords, Voyage of the Damned) located 149,600,000 kilometres away from the Sun. (COMIC: The Hyperion Empire) At one point the planet was transported to the Medusa Cascade by the Daleks, (TV: The Stolen Earth) and was subsequently towed back to its normal orbit in the Solar system by the TARDIS. (TV: Journey's End) Earth's "constellation" was later shifted across two light-years of space by the Time Lords and renamed "Ravolox" circa 2,000,000 AD, being returned at some later point to its original location. (TV: The Mysterious Planet)

Moon(s)
For much of Earth's history until 2049, a planetoid-sized egg was a satellite of Earth. This egg, known as the Moon, impacted the Earth's tides and eventually hatched in 2049. The creature replaced the Moon's position with a "new moon" - equal in size to the original - when it laid another egg shortly after hatching. (TV: Kill the Moon) By the time of the Fourth Great and Bountiful Human Empire, the Earth had five moons. (TV: The Long Game)

Geology
Earth was rich in many valuable metals and elements. (PROSE: Doctor Who and the Day of the Daleks) It was one of the few sources of quartz in the galaxy (TV: The Pirate Planet) and was also rich in silicon and carbon. (TV: Four to Doomsday)

The planet was not entirely spherical, which meant that Shanghai and Buenos Aires, while technically antipodes, were slightly off. The Blessing ran through the Earth between those two points. (TV: The Blood Line)

Atmosphere and gravity
Earth's atmosphere was 80% nitrogen and 20% oxygen. (AUDIO: The Resurrection of Mars) Carbon dioxide was vital to Earth's lower atmosphere. (TV: The Ice Warriors) Due to human activity, Earth had a lot of toxins and dioxins in its atmosphere, which would have provided decent nutrition for the Nestene Consciousness. (TV: Rose)

The First Doctor noted that Earth's atmosphere and gravity were roughly equivalent to those on Gallifrey. (PROSE: The Rag & Bone Man's Story)

As the Third Doctor noted, with the invention of the motor car came a change in Earth's atmosphere. (TV: Colony in Space) As cars admitted excess carbon dioxide into the atmosphere, causing pollution, they were fitted with ATMOS in the 2009, and didn't emit any at all. What they did add to the atmosphere, though, was clone feed, as it was the Sontarans' plan to convert Earth into a cloning world. This was reversed by the Tenth Doctor and Luke Rattigan, who used an atmospheric converter to clean up the atmosphere again. (TV: The Sontaran Stratagem, The Poison Sky) Nevertheless, the pollution of Earth's atmosphere through global warming reached a point of no return in the early 21st century. (PROSE: Cat's Cradle: Warhead)

Geography
Earth was 70% water. (TV: The Fires of Pompeii, AUDIO: Kings of Infinite Space)

Earth's surface changed considerably over the course of its long history, owing to its high seismic activity. When native life first appeared on the planet, for example, what later became the middle of the Atlantic Ocean was a vast, rocky wasteland. (TV: City of Death)

The actions of humans, specifically their pollution, also had a major effect on the geography of the world. Earth nearly became an ocean world in the early 22nd century. (AUDIO: Kings of Infinite Space) By the 26th century, the seas of Earth had been polluted, irradiated, set on fire and boiled off into a thick sludge. (PROSE: Ship of Fools) By the 52nd century, winters no longer occurred due to global warming. (PROSE: The Frozen) However, in the days of the Second Great and Bountiful Human Empire, the Earth was far less polluted than in the twentieth century. (TV: The Daleks' Master Plan)

Over millions of years, continental drift caused the surface of Earth to change radically, creating such features as the Arctic Desert and the Los Angeles Crevasse. The National Trust installed gravity satellites to hold back the expanding Sun, from a now uninhabited Earth. They also shifted the continents back to their earlier positions, a planetary style known as "Classic Earth", which took billions of years. It stayed like this until the planet's final destruction (TV: The End of the World) in the year 5,000,000,000. (TV: New Earth)

Sapient native species
Several sapient and semi-sapient species evolved on Earth, though the most important and influential ones were the humans and Earth Reptiles, known as Silurians. (PROSE: Love and War, TV: Cold Blood)

Other sapient species native to Earth included the Fairies (TV: Small Worlds), Sidhe (PROSE: Autumn Mist), the dolphins (PROSE: Island of Death), the Carpanthans (COMIC: The Fishmen of Carpantha), the Mermen (COMIC: Guests of King Neptune, AUDIO: Cryptobiosis), the Tuskens (PROSE: Mad Dogs and Englishmen) and the Erithians (AUDIO: The Caves of Erith).

Flora and fauna
In its long history, many species had evolved on Earth. By the 21st century, over three hundred billion species of animals had already evolved and gone extinct. (PROSE: The Last Dodo)

The Fourth Doctor stated that Earth was the only planet in its galaxy where oak trees grew. (TV: The Android Invasion) Botanists tried to seed oak trees on other colony planets, but found that they always died. (AUDIO: The Unknown)

The Trees of Cheem, a race of intelligent humanoid trees, originally descended from the tropical rainforests of Earth. (TV: The End of the World)

Before life
Following Rassilon's Eternal War against the Yssgaroth, (PROSE: The Pit, TV: State of Decay) the Time Lords tracked down all the openings to the Yssgaroth's universe and closed them off with containment shells disguised as planets, (PROSE: Interference - Book One, The Book of the War) the Earth being one of these. (PROSE: The Book of the War)

One account stated that the Sentience existed like a fissure in the universe, around which the Earth formed, trapping it, (PROSE: Nightshade) while another account claimed Earth formed circa 4.6 billion years BC around a Racnoss spacecraft which carried the last of their ancient race. The craft drew in surrounding asteroids and shaped them into a planetary body. (TV: The Runaway Bride)

Soon afterwards, the Eleventh Doctor arrived on a Tuesday, in what he described as "6 billion years ago." At that time, the Earth was hot and volcanic. (TV: Hide)

Around 3 billion BC, the consciousness of the Sou(ou)shi settled on Earth and went into dormancy. (PROSE: Venusian Lullaby)

Creation of life
Native life eventually developed due to the explosion of a Jagaroth spaceship circa 400 million BC, (TV: City of Death) the experiments of the Archaeons using red lightning to seed the Earth and turn it into an ordered "garden" circa 450 million BC, (AUDIO: The Beginning) or both.

First terrestrial life
At the "dawn of time", the dominant life-forms were small aquatic reptiles dwelling in marshes in volcanic areas. However, eventually, one particular reptile one day decided to climb onto land and adopt a terrestrial lifestyle. The whole of the evolution of subsequent terrestrial life hinged on this decision by the animal: had it not decided to do so, although terrestrial life still would have evolved, it would have done so in different directions and not produced humans. This was tested when two human scientists experimenting with time travel tried to send back a camera to that fateful day, only for the camera to knock the reptile back into the water. (COMIC: Dr. Who's Time Tales)

Dinosaurs, Silurians and Sea Devils
Various species of saurian creatures dominated the planet until circa 65 million BC when a freighter from 2526 time-warped to this period and exploded in the upper atmosphere. The resulting clouds of dirt and smoke obscured the Sun, lowering the temperature and causing mass extinctions. (TV: Earthshock)

An intelligent species of reptiles flourished and then went extinct. (PROSE: All-Consuming Fire) Reptilian Silurians (TV: Doctor Who and the Silurians) and Sea Devils (TV: The Sea Devils) were also active and were the dominant species on Earth. During this time, the red leech also existed and was the Silurians' most virulent enemy. They were believed to have gone extinct during this period, but at least one survived to the year 1893. (TV: The Crimson Horror)

The reign of the Silurians and Sea Devils came to a final end when the small planet (later known as Earth's primary satellite, the Moon) entered Earth's orbit. (TV: Doctor Who and the Silurians) Some of the reptilian scientists, such as Dr Wolik, calculated that the Moon would closely approach Earth, drawing off the atmosphere (PROSE: Doctor Who and the Cave-Monsters, COMIC: Twilight of the Silurians) and destroying "all life". (TV: Doctor Who and the Silurians) The Third Doctor repeated the claim to Marc Marshall that the Silurians built the shelters when they thought the planet would "suck away" Earth's atmosphere as it rushed by. (PROSE: The Scales of Injustice) Conversely, the Fifth Doctor recalled that the Silurian astronomers predicted that Earth was about to be "struck" by the planet at the time, (PROSE: Warriors of the Deep) and the Eleventh Doctor described the trajectory of the planet the astronomers had predicted as a "crash course". (TV: Cold Blood) The reptiles went into suspended animation until the atmosphere returned. Because the atmosphere never went away, they stayed in hibernation for millions of years. (TV: Doctor Who and the Silurians) Nonetheless, the effects of the Moon's arrival, while never completely pulling the atmosphere away, caused huge tidal waves to sweep over its continents, volcanoes to erupt, earthquakes bringing mountains down and cyclones to rage across the planet. Millions of humanity's ape ancestors drowned or were blown into rocks by the winds, but some survived and multiplied. (PROSE: Doctor Who and the Cave-Monsters) During millions of years of hibernation, the reactivation machinery of the reptiles' hibernation units deteriorated. (TV: The Sea Devils) One account implied that the Moon was already in orbit before intelligent life had developed, (AUDIO: The Beginning) while another stated that it was an egg laid by an alien species around 100 million BC. (TV: Kill the Moon)

Apes, regarded by the reptiles as pests, eventually evolved into the species known as humans, given a substantial jolt forward when the Fendahl Core arrived in Africa circa 12 million BC. (TV: Image of the Fendahl)

The rise of human civilisation
Human civilisation evolved quickly, assisted (either accidentally or directly) by the Dæmons, (TV: The Dæmons) the various temporal fragments of Scaroth, (TV: City of Death) the predatory nature imparted to humans by the Fendahl, (TV: Image of the Fendahl) and the occupation by the Silence. (TV: Day of the Moon) Scaroth claimed responsibility for the inventions of fire and the wheel; (TV: City of Death) the Silents claimed they were on Earth since that point. (TV: Day of the Moon) The Osirans apparently had an influence on Earth around 5000 BC, inspiring many aspects of Ancient Egypt and imprisoning one of their number, Sutekh, in Egypt. (TV: Pyramids of Mars) The Third Doctor said that the Dæmons helped Homo sapiens "kick out" Neanderthal man. He mentioned the Greek civilisation, the Renaissance, the Industrial Revolution, and various myths, gods and devils including Khnum and the Horned Beast as being inspired by the Dæmons. (TV: The Dæmons) In 1500 BC, the Were Lords settled in Greece and lived among humanity for thousands of years, being worshipped by early humans and being remembered as myths. (AUDIO: Brightly Shone The Moon That Night)

For "a half a million years", humanity systematically killed one another in conflicts. (TV: The War Games) Human beings' predatory and aggressive nature was evident in the many conflicts which humans fought amongst themselves throughout much of their early history, such as during the siege of Troy, the Dark Ages and the American War of Independence. (TV: The Mark of the Rani) Other conflicts, including World War I, the English Civil War, the American Civil War, the Mexican Civil War, the Crimean War, the Boer War, the Russo-Japanese War, the Thirty Years' War and the Peninsular War were also exploited by the War Lords, who kidnapped human soldiers from these various conflicts in Earth history for use in their war games. (TV: The War Games)

20th and 21st centuries
The First Doctor's companion Vicki Pallister, who was from the 25th century, did not consider early 20th century Earth to be much more advanced than Rome in the 1st century. Barbara Wright took offence at this remark. (AUDIO: Starborn)

The conflicts known as the First and Second World Wars and the Cold War would be particularly significant in the 20th century. The development of nuclear weapons increased international tensions in the late 20th century even more. In the 1980s nuclear war between the Soviet Union and the United States seemed imminent. (TV: Cold War) This threat was somewhat alleviated when the great powers entrusted their nuclear launch codes to the United Kingdom for safe-keeping (TV: Robot), and again when the planet came under the rule of the World Zone Authority in the early 21st century. (TV: The Enemy of the World)

In July 1969, the Eleventh Doctor made the humans subconsciously turn against the Silents and drove them off the planet, leaving behind their network of underground tunnels and several of their crafts. It was at this time that humans sent their first people on the Moon. (TV: Day of the Moon) Scaroth was killed in 1979. (TV: City of Death)

The space race, partially inspired by the Silence, (TV: Day of the Moon) was of great significance: while Earth had been visited by aliens many times throughout its history, the launching of space probes made such visits more frequent, as Homo sapiens began drawing attention to themselves. (TV: Spearhead from Space) These visits also tended to be more openly hostile. Earth was saved from conquest or outright annihilation often only through the intercession of the Doctor or the secret (prior to the 21st century) organisation Torchwood. An attack by the Great Intelligence would finally force the Earth's governments to agree on a unified response to aliens: the United Nations body known as UNIT. (TV: The Web of Fear, The Invasion) Despite this increase in invasions, a number of aliens that arrived were benevolent.

The governments of Earth, as well as the Doctor, UNIT, Torchwood, and (by the 21st century) Sarah Jane Smith and her Ealing group, tried to keep these invasions a secret. UNIT was officially a counter-terrorist group and had several incidents explained as terrorism and accidents, though this caused political scandals throughout the 1970s. (PROSE: Who Killed Kennedy) Torchwood used mind-wiping drugs to cover up some incidents, (TV: Everything Changes) while Sarah Jane used her computer Mr Smith to deliberately falsify evidence and news reports. (TV: Revenge of the Slitheen, TV: The End of Time) The Seventh Doctor would remark that these cover-ups were helped by the fact humans didn't want to notice, and were performing self-deception on themselves. (TV: Remembrance of the Daleks)

In the early 21st century, starting with the Slitheen infiltration of 10 Downing Street (TV: Aliens of London), alien incidents became far more blatant. The governments and UNIT would have a random policy of alternately admitting that some aliens existed (TV: The Christmas Invasion, The Sound of Drums, AUDIO: The Coup) and trying to desperately cover things up, such as claiming the Battle of Canary Wharf was because of terrorists planting drugs in water. (TV: Everything Changes) Many humans acknowledged the aliens, while others tried to claim they were fake. (TV: Smith and Jones) However, several further events, most notably the forced relocation of Earth and a global Dalek assault (TV: The Stolen Earth/Journey's End) and the 456 crisis (TV: Children of Earth) served to finally convince the populace at large that humanity was not alone in the universe. Subsequent events, however, in particular the manifestation of the time field, removed some of these events from the memories of many, if not all humans; (TV: Flesh and Stone, The Big Bang) the Doctor ultimately rebooted the universe and Earth's history. (TV: The Big Bang)

In 2011, Earth's political and social climate changed heavily following Miracle Day, where the human race stopped dying as a result of a morphic field and yet continued to age. (TV: The New World, Rendition) This ended when Jack Harkness' blood was fed into the Blessing's antipodes. (TV: The Blood Line) As a result, some countries like India and Pakistan reduced tensions with one another, while others like North Korea started mobilising troops and the legal definition and practical use of attempted murder and suicide were thrown into chaos. (TV: The New World, Rendition, The Categories of Life, The Middle Men) Various governments established the categories of life, throwing category 1s and 2s into overflow camps and incinerating category 1s inside Modules. (TV: The Categories of Life) This quickly became public knowledge. (TV: The Middle Men)

Around 2018, Earth had a population of 7 billion. (TV: The Lie of the Land, The Battle of Ranskoor Av Kolos, Resolution)

From 2019 to at least 2059, Earth went through a period of chaos: climate change, ozone degradation, the "oil apocalypse", the Great Cataclysm, a Korven invasion (TV: The Waters of Mars, The Eclipse of the Korven) and the increased weight of the Moon causing high tide everywhere all at once. (TV: Kill the Moon) Humanity faced extinction, but not only survived; they achieved major advances in space travel (TV: The Waters of Mars) and developed weather control technology. (TV: The Moonbase) In 2058, Earth's first colony on Mars was established by Adelaide Brooke; (TV: The Waters of Mars) humanity would go on to create an early form of transmat (TV: The Seeds of Death) and lightspeed travel. (TV: The Waters of Mars) To cope with the depleted oil supply, humans began drilling off world, taking oil from other planets. (TV: The Infinite Quest)

In late 21st century, the United States of America and Eurozone began showing hostilities to each other (PROSE: Trading Futures) and by 2084, there were again two vast power blocs in conflict and the threat of nuclear war. (TV: Warriors of the Deep) According to one account, the tensions between the competing blocs ended with the Martian assault of 2086, when Paris was destroyed. A Thousand Day War against a common alien enemy united humans and planted the seeds for a united Earth. (PROSE: Transit) However, a different account showed that all of the Martians were either destroyed after — in the words of Harold — "something to do with T-Mat on the Moon" or were inactive and in suspended animation on Deimos and in the Sol system's asteroid belt. (AUDIO: Deimos)

However, other accounts differed on this, stating that, among other things, Mars was entirely populated by human colonists by the 23rd century, with the native Martians, the Ice Warriors, already becoming — in the words of Ice Warrior expert, Professor Schooner — "extinct for hundreds of years", when, according to what Gregson Grenville had learnt from school, "they were all melted when their invasion fleet spiralled into the sun".

This account showed extant Ice Warriors, but all were in suspended animation for — according to the Eighth Doctor — "many millions of years" at the time both the destruction of the fleet and the Thousand Year War were purported to have happened. (AUDIO: Deimos)

Humanity travels to the stars
In 2089, Earth made its first interstellar flight which was flown by Susie Fontana Brooke and it led her to Proxima Centauri. (TV: The Waters of Mars) In 2095 a full-scale human colonisation of Mars began to be colonised for the wealthy minority humans. (PROSE: Beige Planet Mars) Four years later, the governments of Earth, in answer to global warming, had taken vast sections of the Arctic and Antarctic and placed them inside huge domes called Snowglobes. (PROSE: Snowglobe 7)

In 2151, Earth went through a bee invasion. (PROSE: The Secret in Vault 13)

In the 22nd century, Earth suffered the rise of large corporations which would occasionally wage active war against each other, energy crises and the collapse of the tourist trade. In 2156, Earth Central declared bankruptcy and the corporations (under the Earth Alliance of Corporations) took control of the planet. Despite this, Earth's colonisation of the galaxy continued to advance. The Adjudicators were established to enforce Earth law on the colonies. (PROSE: Lucifer Rising)

22nd century Dalek invasion
The 22nd century Dalek invasion proved devastating to Earth. First, the Daleks wiped out fifteen colonies; (PROSE: Lucifer Rising) next, they released a plague across the Earth. Over a six-month period, Africa, Asia and South America were almost wiped out; humanity was barely able to resist when the Daleks arrived. (TV: The Dalek Invasion of Earth) New York City and many other cities were destroyed. (TV: The Chase) For ten years, the remaining inhabitants of Earth were terrorised by the Dalek forces, who enslaved many and turned others into Robomen, while the Daleks attempted to turn Earth into a mobile dreadnought. Only a handful of resistance groups existed.

Following the defeat of their grand scheme (TV: The Dalek Invasion of Earth) and the shattering of their solar system blockade in the Battle of Cassius, the Daleks left Earth. The planet remained divided into feudal kingdoms for a time, as Earth refused assistance from the colonies; (PROSE: Legacy of the Daleks) large conglomerates, however, stepped in to rebuild the Terran Security Forces. (PROSE: The Final Sanction) The invasion killed about two-thirds of Earth's population. (AUDIO: An Earthly Child) Thirty years after the invasion, the Earth Council existed as a fledgling government, but anti-alien organisations like Earth United began to attract many youths to their cause. (AUDIO: An Earthly Child) Earth was finally rebuilt when other ships from other human colonies arrived to offer their aid. (PROSE: The Janus Conjunction) The Daleks, during the 2190s, invaded Earth again under the Leadership of the Dalek Time Controller, after the renegade Time Lord the Monk spread another virus. They dug up much of North America, hoping this time to move Earth through time and space for the viruses from the Amethyst Viral Containment Station, turning Earth into a plague planet. This plan was averted when Lucie Miller crashed a Dalek Saucer into the mines at the cost of her life. (AUDIO: Lucie Miller/To the Death)

Earth empires
In the early 23rd century, Earth was still reeling from the Dalek invasions and was dominated by corporations, such as Drake Interplanetary which was taken over by in 2223 and became the most powerful company on the planet. By this point, the planet's defences included the Outer Space Defence Halo. (AUDIO: Faustian) The Daleks attempted another invasion, but the Parliament called it off after the Dalek flying saucer sent to establish a forward base in London was met with resistance from the Master. (AUDIO: Vengeance)

Earth recovered and a major "break-out" of colonisation took place. (PROSE: The Romance of Crime) During this century, global warming caught up with the planet, resulting in three quarters of the Earth’s landmass being drowned by water. London was among the flooded cities, with sub-aquatic community Poseidon 8 being established in its ruins. (GAME: Shadows of the Vashta Nerada)

In time the planet formed a unified government and an Earth Empire emerged. This dominated most of Mutter's Spiral for over 500 years. This empire at times came into military conflict with other space powers, particularly the Draconians, (TV: Frontier in Space) Cybermen (TV: Earthshock) and the Korven. (TV: The Korven) It often employed oppressive and disenfranchising policies on the indigenous inhabitants of its colonies. (TV: The Power of Kroll, The Mutants) Alongside Draconia, Earth would fight and win the Second Dalek War. Before the war, Earth and the Empire was overseen by a president, (TV: Frontier in Space) but from the late 26th century it was ruled by a Divine Empress. (PROSE: Cold Fusion)

By the 28th century, Earth was commonly referred to as "Old Earth" by the inhabitants of its colonies such as Nocturne. (AUDIO: Nocturne)

In the 29th century, Earth's environment was largely destroyed by solar flares. Humanity fled the planet on giant spaceships, returning when the solar flares stabilised. Autonomous nations returned during the crisis, as countries like the United Kingdom constructed their own, specific refuge ships. (TV: The Beast Below) The first ship to return to Earth after the flares had passed was the SS Lucy Gray. (GAME: Return to Earth) The United Kingdom was still travelling on its refuge ship by the 33rd century. (TV: The Beast Below)

By the 30th century, Earth was again the centre of the Empire. Overcities now hovered above the surface to house the rich, leaving the poor and alien on the polluted surface with the decaying former cities like London. In 2957, Icaron radiation from a Hithis ship held by Tobias Vaughn sparked off a wave of psychotic murders which escalated to Overcity riots and some cities falling from the sky.(PROSE: Original Sin, AUDIO: Original Sin) Unrest among the subjugated alien races, instabilities in the Empire's political and economic structure, and ecological damage to Earth eventually led to the decline of the Empire. (TV: The Mutants, PROSE: The Sorcerer's Apprentice) After Leabie Forrester became Empress, (PROSE: So Vile a Sin) she dismantled the Empire within five years, causing the former colonies to abandon Earth. (PROSE: Dependence Day)

The Kustollon Igrix recalled that in 3046, the Kustollons of Kustollia fought the humans of Earth in an "enormous, terrible battle" over disputed territories in the Perseus arm. The humans won using a virus developed from Peter and Charlotte Cobb's research which disabled the Kustollons' biotechnology. According to the Ninth Doctor, Earth had collapsed and took centuries to recover from famine, plague and misery. (COMIC: The Love Invasion)

In the 32nd century, Earth was a founding member of the Galactic Federation. (PROSE: Legacy)

By the 36th century the Earth Alliance, a loose alliance of Earth and human colonies, existed. In 3562 the Alliance defeated the Knights of Velyshaa. (AUDIO: The Sirens of Time) The Alliance fought a war against the Eminence. Just as it appeared the Alliance had won, used the Eminence to takeover Earth. His rule was overthrown by the Eighth Doctor who turned the Eminence against him and then dispersed it. (AUDIO: Rule of the Eminence)

In the late 40th century, Earth was among the "Big Four" powers in an alliance against the Dalek invasions, when it was decided to found the Space Security Service (SSS). (PROSE: The Outlaw Planet)

By the year 4000, Earth and its dominions were ruled by a Guardian of the Solar System, with the Space Security Service handling military intelligence. The incumbent Guardian, Mavic Chen, plotted with the Daleks to form an alliance against Earth which was exposed by the First Doctor and SSS agent Sara Kingdom. (TV: The Daleks' Master Plan) Years later, the Tenth Doctor was brought to Earth by SSS agents Anya Kingdom and Mark Seven to investigate George Sheldrake and his time tunnels. (AUDIO: Buying Time) Due to the meddling of the Nun, Sheldrake’s tunnels unleashed a temporal catastrophe on Earth as different time periods collided until the Doctor was able to resolve the situation with Sheldrake’s equipment. (AUDIO: The Wrong Woman)

Mavic Chen’s descendants brought down the Galactic Federation's democracy (PROSE: The Crystal Bucephalus) and the Earth-ruled Second Great and Bountiful Human Empire took its place. During this time the enslavement of the Ood as a servant class occurred. (TV: Planet of the Ood)

Despite the efforts of the Earth Alliance, during Second Great Dalek Occupation Earth fell to the Daleks once again. (AUDIO: ”Death to the Daleks!”) In the ensuing Enemy-Alliance Dalek War, the Daleks continued to occupy Earth and it eventually became their last stronghold in the Milky Way. After the Daleks and Alliance made a truce to fight the Alliance Daleks together, Susan Mendes was taken to Earth by the Dalek Supreme so the Dalek Emperor could be retrieved from her mind. After the retreat of the Alliance Daleks back to their universe, Kalendorf travelled to Earth to confront the Emperor, correctly inferring it was planning to break the truce as soon as it was opportune. Kalndoef initiated the Great Catastrophe that wiped out the Dalek Empire, devastating Earth and its colonies in the process. (AUDIO: Dalek War: Chapter Four)

In the 45th century, Earth became uninhabitable. (AUDIO: Plague of the Daleks)

By 5000 Earth was experiencing a Second Ice Age but was populated. The populace was divided into advanced national alliances resulting in World War VI. (TV: The Talons of Weng-Chiang, AUDIO: The Butcher of Brisbane, PROSE: Emotional Chemistry) This time period saw the Great Breakout, where humans began spreading out from Earth in great numbers. (TV: The Invisible Enemy) According to one account, in the 51st century Earth was engulfed by solar flares. (COMIC: The Keep)

In the time period of the Doctor’s companions Samson and Gemma Griffin, Davros unleashed a mutagenic virus on Earth. As it spread Davros offered his assistance to governments, eventually resulting in the creation of a new Dalek army which occupied the planet. The Eighth Doctor arrived on the occupied planet and exploited Davros’ split personality and a virus lethal to all life that Davros had created to bargain with the Daleks for their withdrawal from Earth. (AUDIO: Terror Firma)

Later events
In the 59th century Earth was protected from solar flares by shields, which also blocked the Moon. (AUDIO: Brightly Shone The Moon That Night) Earth's inhabitants at this time were obsessed with a wide range of religions, based around subjects ranging from Christmas to the British Royal Family being lizards to William Shakespeare. (AUDIO: Blood on Santa's Claw) The Were Lords, who had lived among humanity for thousands of years, attempted to takeover to restore their access to the Moon but were banished to a space station. The Sixth Doctor was tricked into helping them escape but prevented them reaching Earth. (AUDIO: Brightly Shone The Moon That Night)

Inspired to seek more biblical solutions in light of the Were Lords' defeat, (AUDIO: Brightly Shone The Moon That Night) the inhabitants of Earth abandoned the planet to solar flares in 6087, leaving Earth uninhabited for 10,000 years. (TV: The Ark in Space) The population of Earth was evacuated in vast starships, while a small number of people were left behind aboard Nerva Beacon to begin the repopulation of the planet once conditions on the surface were suitable for life. Humans elsewhere carried on with another period of colonial expansion under GalSec. (TV: The Ark in Space, The Sontaran Experiment)

While Earth was uninhabited and damaged, it was occupied by the Charrl, who renamed the world Antýkhon. Humans who had survived the flares, referred to as "Hairies", had mutated to adapt to the depleted atmosphere and soil caused by the Charrls' industrial activities. The Charrl occupation lasted some 3,497 years. (PROSE: Birthright) After being awoken by the interference of the Fourth Doctor, Nerva Beacon's evacuees returned to Earth after ten thousand years had passed. They recolonised the planet. (TV: The Ark in Space)

According to one account, by the year 37,166, Earth had been abandoned "since the start of the third era". (PROSE: Doctor Who and the Planet of Evil)

Some time after, Earth was visited by the Usurians, who relocated the dying human population first to Mars and then Pluto. Generations later, humans had thrown off the yoke of Usurian exploitation and returned to Earth. (TV: The Sun Makers)

By the year 200,000, Earth was at its height, covered with megacities and a population of 96 billion. It was the centre of the galactic domain of the Fourth Great and Bountiful Human Empire that stretched across a million planets and species. The Empire had been secretly manipulated and its progress hindered by Dalek survivors of the Last Great Time War, who allowed an alien known as the Jagrafess and his consort, the Editor, control over the planet until they were caught and overthrown. (TV: The Long Game, Bad Wolf, The Parting of the Ways) Earth underwent a century of social collapse and pollution before a full-scale invasion commenced in 200,100, including a bombing campaign which disfigured the continents. The Dalek fleet was destroyed by the Bad Wolf entity. (TV: The Parting of the Ways)

About the year 2,000,000, Earth was relocated two light-years from its proper position by the Time Lords to prevent the escape of aliens from the constellation of Andromeda who had stolen information from the Matrix on Gallifrey. Most of the humans remaining on Earth were wiped out. Those that survived degenerated to a primitive, tribal culture. The planet came to be known as Ravolox, with Earth being completely forgotten. The inhabitants of Ravolox eventually came to know of the true nature and history of their planet and to rebuild their civilisation. (TV: The Mysterious Planet) The prophecy of the Vampire Messiah also used the name Ravolox for Earth. (PROSE: Goth Opera). Although Glitz informed her about Earth being a decimated planet, Mel Bush decided to try and make her way to Earth, intending to pull its scattered populace together and rebuild; six months later, however, she'd become stuck on Avalone. (PROSE: Head Games)

At some point, the planet was known by the name Tellus and was owned entirely by the mining company, Tellac Inc. During this period, the president of the company was the political leader of the planet as well. (PROSE: K9 and the Missing Planet)

At some point in the far future, Earth was a dead planet, (AUDIO: Voyage to Venus) destroyed and "laid barren by wanton waste and foolhardy destruction". (PROSE: The Gallery)

Earth's destruction
In the 57th segment of Time, the last humans left Earth because of the increasing danger that it would fall into the Sun, fleeing to planets such as Refusis II and Frontios. (TV: The Ark, Frontios) This destruction of Earth was dated circa 10,000,000 by The Book of the War and The Human Species: A Spotter's Guide (PROSE: The Book of the War, Of the City of the Saved...) and circa 12,000,000 by some future historians. (PROSE: The Brakespeare Voyage) In Earth's absence, humanity was deprived of a common cultural reference point and the posthuman era began. The posthuman Arcadian movement recreated Earth on 28,000 Earth-like displays, of which many were called "New Earth". (PROSE: The Book of the War)

Other accounts indicate Earth still existed billions of years later, by which time the Sun had exhausted its hydrogen supply and turned into a red giant. It was restored to a "classic" Earth by the National Trust. As the Sun grew, the National Trust financed technology to keep its expansion held back so it would not engulf the Earth. However, funding for the preservation project eventually ran out and the National trust withdrew its protection. Earth was finally destroyed by the expanding Sun (TV: The End of the World) in the year 5,000,000,000. (TV: New Earth) However, at some point, humanity had settled on a planet called New Earth, which had a similar size, orbit, and atmosphere to Earth. According to one account, humanity had relocated to New Earth long before the destruction of Earth. (COMIC: Agent Provocateur) According to another account, the Tenth Doctor said that in 5,000,000,000, "as soon as the Earth burn[t] up", the human race, who at this point were "spread out across the stars", got nostalgic and then found New Earth after forming a big revival movement. (TV: New Earth) Humanity outlived their original homeworld for tens of trillions of years, up until the end of the universe itself (TV: Utopia, Kill the Moon) and beyond. (PROSE: Of the City of the Saved..., etc.)

According to yet another account, the end of the world saw a malevolent government hunting down all survivors of humanity, with cities such as London becoming derelict and overrun with vegetation, while Sol slowly imploded in a way that was visible from the Earth and did not immediately destroy the planet. The last two survivors not belonging to the government were Lucy Wilson and Hobo Kostinen. (PROSE: Assessment Day)

Alternate timelines
Earth experienced various alternate timelines.

In alternate 20th centuries
In a timeline accidentally created by the Seventh Doctor and Ace in 1944, the Nazis won the Second World War, resulting in Germany becoming the dominant power on Earth. In 1962 of this timeline, the regenerated Doctor tricked Nazi scientist Elizabeth Klein into travelling back in time to 1944, causing his past self and Ace to prevent this timeline coming to pass. (AUDIO: Colditz, Klein’s Story)

Sarah Jane Smith was tricked by the Trickster into travelling back in time to 1951 where she averted her parents’ deaths. This allowed the Trickster to manifest on Earth through the Abbot's Gateway and devastate the planet, enslaving the few surviving humans. Sarah Jane and her parents averted this by correcting the timeline. (TV: The Temptation of Sarah Jane Smith)

In one timeline, the Daleks found the Eye of Time, invaded Earth in 1963 and wiped out humanity. This timeline was averted by the Eleventh Doctor and Amy Pond, by preventing the Daleks from resurrecting their Emperor along with the rest of Skaro and launching the attack in the first place. (GAME: City of the Daleks)

On one occasion, guerrilla fighters from an alternate timeline of 22nd century Earth attempted to prevent their own future and instead caused it. Shura bombed Auderly House where Sir Reginald Styles was holding the second World Peace Conference, vital to preventing World War III. As a result, many world leaders were killed and a series of wars devastated the planet, killing seven-eighths of the population. By the 22nd century, the Earth was under the rule of the Daleks. After travelling to this future, the Third Doctor and Jo Grant pieced together what had actually happened to cause the future which had previously been blamed upon Styles. After being informed of the truth, Shura sacrificed himself to blow up a Dalek attack force once Auderly House was emptied, changing the future. (TV: Day of the Daleks)

On another occasion, the release of Sutekh in 1911 meant that by 1980 the Earth would become a desolate planet circling a dead sun. The Fourth Doctor showed this to Sarah Jane Smith, and by causing Sutekh to age to death before he could escape, this timeline was averted. (TV: Pyramids of Mars)

In one alternate timeline, the Earth was devastated by the Daleks of the Mutant Phase before they were killed from ingesting a pesticide. The Fifth Doctor realised that the Dalek Emperor bringing the pesticide cure back in time to the beginning of the so-called Mutant Phase created this timeline as the cure was not effective on the early stages of the mutation. The Dalek Emperor destroyed the cure and averted the Mutant Phase and this future. (AUDIO: The Mutant Phase)

In another alternate timeline created by the Elder Gods in the hope of destroying Earth, Vladimir Kryuchkov became the General Secretary of the Communist Party of the Soviet Union instead of Mikhail Gorbachev in 1985. On 9 November 1989, World War III broke out between the United States and its allies including the United Kingdom on the one hand and the Soviet Union on the other hand. Given that nuclear weapons were used by both sides, hundreds of millions of people were killed in the conflict. This timeline was ultimately negated by the Seventh Doctor except for in a pocket universe where the Doctor trapped the two Elder Gods responsible and, accidentally, his companions Ace and Hex. (AUDIO: Protect and Survive)

In an alternate timeline, the Earth was a polluted world covered in a chemical slime. From this world sprang the haemovores with the Ancient One being the last by the year 500,000. After Fenric brought the Ancient One to 1943 Earth, he attempted to get the Ancient One to fill the oceans with poison which would create this future. The Seventh Doctor convinced the Ancient One of the truth and it sacrificed itself to defeat Fenric and change its future. (TV: The Curse of Fenric)

opening the Eye of Harmony from the Doctor's TARDIS in San Francisco on 31 December 1999 led to Earth being sucked into the Eye at midnight. However, when Grace Holloway helped the Eighth Doctor put the TARDIS into a temporal orbit, this timeline was averted. (TV: Doctor Who)

In alternate 21st centuries
In an alternate timeline created by Rassilon granting the Cyberiad the means to conquer all of history, the Cybermen assimilated the Silurians in Earth's prehistory, creating the Cyber-Silurians, and used their technology to build a fleet of Cyber-Arks with which they seeded the galaxy with Cyber-Technology. In 2006, the Cybermen invaded Earth and converted all of humanity into Cyber-Warriors within three days via use of the techno-virus, an airborne cyber-conversion virus; as a result, the Earth was transformed into the "Cyber-Earth". The Ninth Doctor, Rose Tyler and Captain Jack Harkness investigated the Cyber-Earth to ascertain how the Cybermen invaded Earth in such a time frame, as well as to recover the Doctor's TARDIS from the Cyber-Warriors' base at St Paul's Cathedral; after learning of the techno-virus from witnessing it cyber-convert Rose, the Doctor, left with no other options, attempted to rupture the Heart of the TARDIS to destroy the TARDIS and the Cyber-Earth, but the energy was siphoned away by the Gallifreyan Cyber Fleet during their invasion of Gallifrey at the end of the universe. This timeline was ultimately averted when, during the Cybermen's invasion of Gallifrey, the Twelfth Doctor and a betrayed Rassilon used the harvested regeneration energy stored in the Eye of Harmony to restore the original timeline via the Cyberiad's dominance across all of time and space. (COMIC: Supremacy of the Cybermen)

After becoming Prime Minister of the United Kingdom, the incarnation of the Master orchestrated the Toclafane invasion, decimating the human population of the Earth and putting the planet under his rule to use as a stepping stone to take over the universe. Within a year, the Earth was quarantined by the rest of the universe as going through "terminal extinction." After the defeat of the Master thanks to the efforts of Martha Jones, Captain Jack Harkness and the Tenth Doctor, this timeline was reverted and became known as The Year That Never Was. Only those on the Valiant when time was reversed remembered these events. (TV: The Sound of Drums, Last of the Time Lords)

When a member of the Trickster's Brigade made Donna Noble change a seemingly small decision in her life, it resulted in an alternate timeline where the Doctor had died on Christmas, 2007. Because of this, many deaths occurred that he would have otherwise stopped. These deaths included most of the population of London when a spaceship replica of the Titanic crashed into the city. The timeline was put back to rights after Rose Tyler, with the help of UNIT, sent Donna back in time to ensure she made the decision to turn left instead of right and take a job at H.C. Clements. (TV: Turn Left)

The Kovarian Chapter of the Silence (TV: The Time of the Doctor) exploding the TARDIS in 2010 led to the collapse of the universe, with Earth's history being barely held together by the TARDIS as it exploded throughout history. The Doctor was able to reboot the universe by flying the Pandorica into the exploding TARDIS. (TV: The Pandorica Opens / The Big Bang)

When River Song refused to shoot the Eleventh Doctor at Lake Silencio on 22 April 2011, a fixed point in time, time collapsed, creating a timeline where all of history was happening at once. The Doctor revealed to River he was really miniaturised and hiding inside the Teselecta, causing her to perform the shooting and abort this timeline. (TV: The Wedding of River Song)

In their attempts to defeat the Tenth Doctor, the Time Sentinels created a timeline where Earth was destroyed in the 21st century to try and trap him. Seeing the trap for what it was, the Doctor deliberately avoided investigating this timeline. (COMIC: The Good Companion)

Undated alternate timeline Earths
In one possible future, global warming, economic collapse, mass migration and nuclear war turned the Earth into an uninhabitable wasteland populated by the Dregs, the mutated remnants of humanity. The Earth was declared an orphan planet and designated Orphan 55. The Thirteenth Doctor and Team TARDIS visited Orphan 55 after Graham O'Brien won a trip to the Tranquility Spa. After Bella's sabotage put the spa in danger from the Dregs, Team TARDIS learned the truth before managing to flee the planet with the survivors. The Thirteenth Doctor told her companions that Orphan 55 was just one possible future for the Earth and it could be avoided if humanity made the right choices. (TV: Orphan 55)

Culture
Human culture was highly diverse. Natives of the Earth used a wide variety of languages, including Latin, (TV: The Fires of Pompeii) Greek and Hebrew (PROSE: Byzantium!) in the ancient times and English, (TV: The Two Doctors) Mandarin (TV: Children of Earth: Day One) and Russian (TV: Cold War) in the 20th and 21st centuries. Some of the Earth languages were later used on other worlds too, for example Hebrew was spoken on the human colony of Ha'olam. (PROSE: Dreamstone Moon)

The Earth was home to many influential human artists, such as Leonardo da Vinci (TV: City of Death) and Vincent van Gogh. (TV: Vincent and the Doctor) Influential Earth musicians included Ludwig van Beethoven, (PROSE: Gone Too Soon) Wolfgang Amadeus Mozart, (AUDIO: My Own Private Wolfgang) and the Beatles. (AUDIO: 1963: Fanfare for the Common Men)

Religions
Diverse deities were worshipped on the planet. The ancient Romans worshipped several gods, including Vulcan and Venus. (TV: The Fires of Pompeii) Some Earth deities were in fact advanced beings from outer space, like the Osirans and Olympians worshipped by the Egyptians and Greeks respectively. Eventually however, these cults started to lose their influence because of the spread of Christianity. (PROSE: Byzantium!)

Without specifying the species, the Tenth Doctor said that Earth, like a million other worlds "right across the universe", had "the representation of the horned beast" in its myths and legends. The Beast claimed to be this "devil", along with all of the others in every religion which had such a figure. (TV: The Satan Pit)

Politics
In its early period, the Earth lacked a united planetary government, being organised into nation-states instead. (TV: The Sontaran Stratagem) Many of those societies were ruled by kings, like Ur (PROSE: Happy Endings), Macedon (AUDIO: Mask of Tragedy) of the ancient era, France in the 18th century (TV: The Girl in the Fireplace) and England well into the 21st. (PROSE: Revenge of the Judoon) Other forms of government, like that of the United States of America, which was led by a President, were however by no means unknown. (AUDIO: The Eye of the Scorpion)

Earth was finally unified into a world state after the Thousand Day War against the Ice Warriors in the late 21st century. A brief relapse into warring feudal states followed the Dalek occupation before the Earth was again united. (PROSE: Legacy of the Daleks) It was also around this time that Earth formed the Alliance with Alpha Centauri and other nearby systems, its first formal alliance with alien species. (PROSE: Original Sin, Lords of the Storm)

The United Earth government quickly became corrupt and on the payroll of powerful financial concerns like INITEC, the Galatron Mining Corporation, the AMORB Project and especially IMC, looking the other way as these organisations victimised indigenous species and human colonists alike on the outer worlds. (TV: Vengeance on Varos, Colony in Space) In time the business policies of these corporations and the political and diplomatic policies of the Earth government became parallel and laid the foundations for the Earth Empire. Law and order was enforced by the Adjudicators. Although Earth was governed by a democratically elected leader, civil liberties in the mid-third millennium were marginalised and critics of the government were frequently sent to the Moon, which was converted from a civilian colony to a prison. (TV: Frontier in Space) In the last centuries of the third millennium, the Republic became an Imperial monarchy, with the Holy King (or Queen) ruling Earth and its empire. The last Holy Monarch left control of the Earth to a ruling council upon her death, shortly before the Solos Incident. (PROSE: Original Sin, TV: The Mutants)

With the advent of the Second Ice Age and continuing unrest among the colonies, Earth's government collapsed at the turn of the fourth millennium. Feudalism returned on the planet and on many of its colonies. An aristocratic government remained in control of Earth when the Galactic Federation was formed in the later years of the millennium. (TV: The Curse of Peladon) This aristocracy gradually gave way to more democratic forms, but this new era of freedom was short-lived as the Solar System came under the sway of the Chen Dynasty after 4000. (TV: The Daleks' Master Plan, PROSE: The Crystal Bucephalus)

By 4126, Earth was the centre of the Second Great and Bountiful Human Empire, a vast and powerful tri-galactic power. Ood slavery was common and accepted during this period. (TV: Planet of the Ood) A few hundred years after the 36th century, however, it had been replaced by the Earth Alliance, a powerful Earth-centred bloc. This was the main power fighting another Dalek invasion of the galaxy, (AUDIO: Invasion of the Daleks) though Earth itself was conquered for much of the war. (AUDIO: Dalek War: Chapter One) When it was liberated, it became a victim of the Great Catastrophe. (AUDIO: Dalek War: Chapter Four)

After this, the nations of the Earth became completely independent once more. A Sixth World War loomed by the year 5000 between the superpowers of the Icelandic Alliance and Supreme Alliance. This ended with the Supreme Alliance victorious and Iceland occupied. Other important nations at the time included the Commonwealth of Australia, which itself was occupied and the Philippines, which liberated Iceland and defeated the Supreme Alliance. (TV: The Talons of Weng-Chiang) At the same time, Earth was responsible for a new period of space exploration and colonisation. (TV: The Invisible Enemy)

By the 100th century, the Earth was facing civil wars and by the 102nd century it was reformed into the Junta. (PROSE: Synthespians™)

Information on what forms of government existed on Earth during its later periods was scant, owing to the frequent evacuations and resettling by humanity which occurred. During Earth's period as the planet Ravolox, the few surviving humans there appeared to live in a tribal matriarchy somewhat similar to that of the ancient Celts. (TV: The Mysterious Planet)

Economy
Variations of capitalism and communism were practised by Earth humans in the 20th century. (PROSE: History 101)

From the 20th to at least the 40th centuries, much of Earth's economy was dependent on oil, a non-renewable resource, much to the annoyance of the Fourth Doctor. (TV: Terror of the Zygons, The Infinite Quest)

In 2008, the Earth entered a recession. Three years later, the Earth's economy spiralled further following the Miracle, leaving Ireland and Greece bankrupt. (TV: End of the Road, The Gathering)

Towards the end of Earth's history, trees which traced their ancestry to the tropical rainforests had acquired sizeable fortunes, mostly in real estate. (TV: The End of the World)

Place in the universe
The First Doctor was unfamiliar with Earth prior to his departure on Gallifrey. However, his granddaughter Susan Foreman had learned of its existence and that of the solar system in her spatial cartography lessons. (AUDIO: The Beginning)

Earth was the target for many alien invasions. The conquest of the planet was often for one of three reasons:
 * The need for resources
 * The expansion of empires
 * The replacement of a homeworld

The Sontaran invasion of Earth, as well as a previous claim to the planet, was motivated by the actions of the Rutan-Sontaran War. (TV: The Sontaran Stratagem/The Poison Sky, The Time Warrior) The Nimon sought control of Earth due to its position in space allowing for multiple expansions in their Great Journey of Life. (AUDIO: Seasons of Fear)

There were invasions more subtle than a direct military action. Sometime before 2050, a Korven known as Lomax hijacked the British government and ruled over Great Britain. He also used the British government to gain control of many other parts of the world. Those under the British Government's control lived under a corrupt, totalitarian regime. Lomax and his subordinates were killed during their invasion attempt. (TV: The Eclipse of the Korven)

Species that planned on turning Earth into their "New..." planets included the Zygons (TV: Terror of the Zygons, PROSE: Sting of the Zygons), the Cybermen (TV: Silver Nemesis), the Nestene Consciousness (TV: Rose), the Daleks (TV: Evolution of the Daleks), the Pyroviles (TV: The Fires of Pompeii) and the Saturnyns. (TV: The Vampires of Venice)

Parallel universes
Numerous versions of Earth were known to exist in parallel universes.

In his attempts to free himself from his exile to Earth, the Third Doctor accidentally sent himself to a parallel version of the planet, one where a fascist government ruled England. This version of Earth was subsequently devastated by the Inferno Project. (TV: Inferno)

In a cluster of parallel universes numerous versions of Earth ruled by the Roman Empire existed. During the War in Heaven, they gained the technology to create links between worlds leading to them uniting as the Empire of Empires. To counter this, House Mirraflex arranged for numerous versions of Earth where the Nazis won World War II to come together into the Greater German Reich. A war between the coalitions ensued, which resulted in over a billion people dying and the victorious Empire including two thousand versions of Earth. Following the conflict, the barriers between world were reinstated. (PROSE: Warlords of Utopia) Veterans of the eternal war from a Roman Earth later took prisoners from the Doctor’s Earth, encountering the Fourth Doctor. (COMIC: Doctor Who and the Iron Legion, AUDIO: Doctor Who and the Iron Legion)

The Seventh Doctor, Ace and Benny visited a parallel Earth where peace between humans and Silurians had been achieved, overseen by the United Races Intelligence Command. (COMIC: Final Genesis)

The Eighth Doctor once visited a parallel Earth where his life existed as a fictional TV show, Doctor Who. (COMIC: TV Action!) The Eleventh Doctor later encountered a similar parallel Earth home to the TV show Doctor Who. (COMIC: The Girl Who Loved Doctor Who) On one parallel Earth, the TV show Doctor Who did not last long, to the disappointment of its creator Martin Bannister. (AUDIO: Deadline)

After Sabbath's actions caused the barriers between various parallel realities to break down, (PROSE: Time Zero) the Eighth Doctor encountered several different versions of Earth whilst trying to restore his reality, including an Earth where the computer was never invented as part of the efforts of that world's Sabbath to protect his Earth, (PROSE: The Domino Effect) a universe where the Eternines sought to drain Earth's energy to save themselves, (PROSE: Reckless Engineering) and an Earth where time-travel tours were founded which faced invasion by an alternate race of Martians. (PROSE: The Last Resort)

In one universe, Earth was regularly visited by the Doctor, who freely altered its history. (AUDIO: A Storm of Angels)

In the Unbound Universe, Earth endured numerous disastrous alien invasions, fought off by an ill-equipped UNIT without the aid of the Doctor. In 1997, the Doctor was exiled to Earth by the Time Lords but was able to escape and resume his travels, taking Alistair Lethbridge-Stewart along with him. (AUDIO: Sympathy for the Devil)

In another universe, the Doctor hid from the Time Lords on Earth. (AUDIO: Exile)

One alternate version of Earth, in a reality that the Tenth Doctor dubbed "Pete's World", was visited by the Tenth Doctor, Rose Tyler and Mickey Smith. This Earth's Cybus Industries birthed its own faction of Cybermen, (TV: Rise of the Cybermen, The Age of Steel) which led the Twelfth Doctor to count Earth among the many origins of his foes. (TV: The Doctor Falls) A global conflict between humanity and Cybermen ensued, (GAME: Cyber Assault, Save Paris) resulting in them being sealed in their factories. This Earth subsequently began to experience accelerated global warming due to Torchwood’s experiments with a breach in reality, which the Cybermen also used to invade the Earth of the Doctor’s universe. (TV: Doomsday)

In her journeys throughout the multiverse to return to N-Space and find the Doctor, Rose Tyler encountered at least four alternate versions of Earth. One of which lost its version of Sol to the reality bomb, (AUDIO: The Endless Night) one which suffered constant rain due to global warming, a situation suspected to have been engineered by aliens, (AUDIO: The Flood) one where the consciousness of deceased humans was uploaded into machines, (AUDIO: Ghost Machines) and one where the planet faced impending destruction at the hands of planetoid EK56. (AUDIO: The Last Party on Earth)

After recovering a capsule capable of travelling between universes from the Auctioneers, UNIT personnel Osgood and Josh Carter visited a parallel Earth ruled by a totalitarian regime which UNIT served, encountering their counterparts in the process. (AUDIO: False Negative)

In one parallel universe, Earth was conquered by Cybermen of the Cyber-Mainframe who used the human population as batteries. (AUDIO: Telepresence)

In another parallel universe, the Doctor became stranded on Earth in 2039 after losing his TARDIS on the DEEP. (AUDIO: Full Fathom Five)

In the Federation universe, Earth was part of the United Federation of Planets. In 2367, this Earth was nearly assimilated by the Borg Collective at the Battle of Wolf 359 before they were routed. When the Cybermen of the cyber-web invaded this universe, the Eleventh Doctor showed Jean-Luc Picard an alternate timeline where they had claimed Earth by 2533. (COMIC: Assimilation²)

Behind the scenes

 * The first shot of the first scene of Rose (the first story following Doctor Who's extended hiatus) featured a dramatic zoom from Earth orbit into Rose Tyler's apartment. A number of Doctor Who stories have since opened with this same dramatic zoom, including The Christmas Invasion, The Runaway Bride, Smith and Jones and The Eleventh Hour.

Information from invalid sources
Vogsphere Inc. owned the copyright to "Planet Earth". (NOTVALID: Tom Baker stars in John Lloyd's lost Doctor Who adventure, The Doomsday Contract)