BC

BC or B.C. was an initialism used to designate an Earth year's position relative to the epoch known as AD. The term "BC" thus designated a negative number; 100 BC was 99 years before 1 BC. Its positive counterpart was AD.

There was, however, a question as to whether the year 1 BC was followed by the year 0 or the year 1 AD. Some people, including the human chronologist Professor Wagg clearly believed that 1 BC was followed by 0, allowing him to make the claim that the year 2000 was the first year of a new millennium, as did American journalists working for television station KKBE. (DW: Doctor Who) The Eighth Doctor concurred with this opinion. (DWN: Doctor Who - The Novel of the Film) However, the Sixth Doctor (MA: Millennial Rites) and Dave Young (EDA: Escape Velocity) both strongly argued that 1 BC was followed by 1 AD, thus making 2001 the start of the 2nd millennium.

Prehistory

 * Time unknown: A splinter of Scaroth of the Jagaroth lives among primitive man, perhaps Neanderthals, and helps speed up the development of human culture. (DW: City of Death)
 * Time unknown: An Ice Warrior spacecraft crashes on Earth and is buried in ice. (DW: The Ice Warriors)
 * Time unknown: Light comes to Earth to catalog its life forms and preserves Nimrod. (DW: Ghost Light)
 * 100,000 B.C.: The First Doctor, Ian Chesterton, Barbara Wright, and Susan Foreman help the cave-dwelling Tribe of Gum to make fire. (DW: An Unearthly Child) Around the same time, the Dæmons arrive on Earth and begin their experiments with humanity, assisting modern humans in wiping all but a very few Neanderthals. (DW: The Dæmons)
 * 55,519 B.C.: Urbanka's ozone layer collapses, and Monarch's ship departs on its first voyage to Earth. (DW: Four to Doomsday)
 * Circa 40,000 B.C.: Five Euterpians arrive on Earth in Australia and begin setting up a ley line of beacons on the planet's surface which their mother ship can use as a guide to split the planet apart and harvest its core for fuel. A random solar flare destroys the mother ship, and the Euterpian away team is trapped on Earth until the late 20th century. (MA: Invasion of the Cat-People)
 * 35,519 B.C.: Monarch's ship makes its first visit to Earth. Kurkutji and several other aborigines are kidnapped from Australia and converted into androids. (DW: Four to Doomsday)
 * 29,185 B.C.: The Ninth Doctor, Rose Tyler and Jack Harkness encounter a tribe of Neanderthals. (NSA: Only Human)
 * 25,519 B.C.: Monarch's ship returns to Urbanka from its first visit to Earth. (DW: Four to Doomsday)
 * Circa 23,000 B.C.: The Tzun venture out from S'Arl in Beta Centauri and fight a war with the Darklings of Yuggoth. (NA: First Frontier)
 * Circa 20,000 B.C.: Two Krynoid pods arrived in Antarctica and go into hibernation. (DW: The Seeds of Doom)
 * 15,519 B.C.: Monarch's ship makes a second visit to Earth, this time kidnapping Princess Villagra and several other Mayans and converting them into androids. (DW: Four to Doomsday)
 * 10,519 B.C.: Monarch's ship returns from its second visit to Earth. (DW: Four to Doomsday)
 * Circa 10,000 B.C.:
 * The Last Great Ice Age ends, and the Cold goes dormant, to awaken again in early 1963. (TN: Time and Relative)
 * A splinter of Scaroth assists humans in developing the wheel. (DW: City of Death)
 * A war erupts between the planets Hextacosulous Blue and Hextacosulous Green; it will eventually destroy them both. (ST: The Lampblack Wars)
 * The planet of Zolfa-Thura is reduced to a desert in a civil war, leaving only its projector screens. The lone survivor of this conflict, Meglos, goes into hibernation, while the screen's power source, the Dodecahedron, transfers across space to the nearby planet of Tigella. (DW: Meglos)
 * 5519 B.C.: Monarch's ship makes its third visit to Earth, this time kidnapping Lin Futu and other natives of China. (DW: Four to Doomsday)
 * Circa 5300 B.C.: The inhabitants of Uxarieus test their new Doomsday Weapon, detonating a star which becomes the Crab Nebula, visible to Earth's inhabitants around 1054 A.D. Radiation from the weapon poisons the soil and atmosphere of Uxarieus, causing the collapse of the native civilization and the decline of the Uxarieans to a primitive level. (DW: Colony in Space)
 * Circa 5000 B.C.: Horus and his followers track Sutekh and his sister Nephthys across the galaxy to Earth in Egypt where the renegade Osirians are defeated. Sutekh is imprisoned beneath a pyramid, while Nephthys's mind is extracted and placed inside a canopic jar. Egyptian culture from this point is based upon the Osirian pattern, while Wars of the Gods enter many of Earth's mythologies. (DW: Pyramids of Mars, MA: The Sands of Time)
 * 5000 B.C.: A possible date for Mondas's drifting away from it's twin planet Earth and it's solar system on a journey to the edge of space. (REF: Doctor Who: Cybermen, DW: The Tenth Planet)
 * 3019 B.C.: Monarch's ship returns to Urbanka from its third visit to Earth. (DW: Four to Doomsday)
 * 3000 B.C.: A possible date for the first Cyberman divergence, a group of Cybermen known as the CyberFaction leave Mondas while the remaining CyberMondasians remain. (REF: Doctor Who: Cybermen,DW: The Tenth Planet) The CyberFaction heads for Planet 14, eventually developing into a separate group without connection to the CyberMondasians. (NA: Iceberg)

3rd Millennium B.C.

 * Circa 2700 B.C.:
 * A splinter of Scaroth of the Jagaroth lives among the ancient Egyptians, and helps speed up the development of human culture, including the building of the Pyramids. (DW: City of Death)
 * The First Doctor, Steven Taylor, and Sara Kingdom arrive in Egypt, pursued by Mavic Chen and the Daleks and meeting the Monk. (DW: The Daleks' Master Plan)
 * The Seventh Doctor and Ace visit Mesopotamia. (NA: Timewyrm: Genesys)
 * Circa 2600 B.C.: The First Doctor, Susan, Barbara and Ian come to Egypt. Itennu tried to frame them for his murder of Menkaure, but the Doctor was able to stop Iteenu. (IDW: The Forgotten)
 * Circa 2300 B.C.: A splinter of Scaroth assists humans in making the first maps of the heavens. (DW: City of Death)
 * 2537 B.C.: The Atlanteans attempt to trap the Chronovore Kronos, resulting in great destruction and the mutation of one member of the court into a Minotaur. King Dalios forbids any future use of the Kronos Crystal and it is locked away in the temple. (DW: The Time Monster)
 * Circa 2000 B.C.:
 * The Master releases Kronos and destroys Atlantis. (DW: The Time Monster)
 * Cessair of Diplos arrives on Earth, posing as a Celtic goddess in Britain. (DW: The Stones of Blood)
 * Grave robbers steal the canopic jar containing the essence of Nephthys. (MA: The Sands of Time)

2nd Millennium B.C.

 * 1936 BC: Emperor Rovan Cartovall mysteriously disappears. (PDA: The Ultimate Treasure)
 * Circa 1500 B.C.:
 * The Monk assists in the completion of Stonehenge using anti-gravity lifts. (DW: The Time Meddler)
 * The Exxilons visit the planet Yemaya 4. (NA: Sleepy)
 * The Tenth Doctor and June visit Greece. (NSA: The Slitheen Excursion)
 * 1366 B.C.: Bernice Summerfield stops over briefly in Egypt while eluding Robot Ants. She finds a Cult of Sutekh is operating at this time. (NA: Set Piece)
 * 1352 B.C.: A Vondraxian Orb is found in Egypt. When the Vondrax appear to take it back, they take the form of gods. (TWN: Trace Memory)
 * Circa 1200 B.C.:
 * The First Doctor, Vicki and Steven are present at the siege and fall of Troy. Vicki stays behind under the name Cressida to marry Troilus. (DW: The Myth Makers)
 * Some time prior to this, the Rani visits the siege, extracting chemicals from the brains of some of the humans in the camps and thus intensifying some of the conflict. (DW: The Mark of the Rani)
 * About a year later, Cressida and Troilus meet the Eighth Doctor, Charley Pollard and a young William Shakespeare. (ST: Apocrypha Bipedium)
 * 1164 BC: Cressida is living at the Temple of Astarte in Carthage at this time. (CC: Frostfire)
 * Circa 1000 B.C.:
 * The Exxilons visit Earth, influencing the construction of cities in Peru. It is probably some time after this that they begin constructing a living city on their own world, one of the Seven Hundred Wonders of the Universe, whose absorption of all forms of energy brings about the fall of their civilisation. (DW: Death to the Daleks)
 * Horath is overthrown and the galaxy emerges from a tyrannical age known as the Dark Empire, to which all galactic civilisations, save for the most primitive ones, were subject for an unknown amount of time. At this point in history Earth was a primitive planet and is thus spared. (SJA: Enemy of the Bane)
 * A Vondraxian Orb is buried under the arctic. (TWN: Trace Memory)

10th century B.C.

 * 905 B.C.: The Gryphon attacks Babylon, but is trapped by mirrors by the Eleventh Doctor and Amy Pond and deactivated by the sun. (DWAM: In the Stars)

9th century B.C.

 * Circa 800 B.C.: Azal seals himself up within the Devil's Hump, awaiting the day when he shall make his final judgment on humanity. (DW: The Dæmons)
 * Date unknown: three members of the Gorgon race are trapped on Earth and subsequently become the subject of ancient Greek legends, particularly Medusa, who would continue to live on earth for the next 3,000 years. (SJA: Eye of the Gorgon)

6th century B.C.

 * 575 B.C.: Bigon is born in Greece, probably in Athens. (DW: Four to Doomsday)
 * 570 B.C.: Bernice Summerfield visits ancient Babylon. (NA: Walking to Babylon)
 * 519 B.C.: Monarch's ship visits Earth, kidnapping Bigon and several other Greeks and converting them to androids. This is the first visit during which the Urbankan meets actually resistance. (DW: Four to Doomsday)
 * Circa 500 B.C.: A Thraal ship accidentally lands on a garden of Olabrian joy-luck crystals, leading to a war with the Olabrians and their eventual destruction. (BNA: Ship of Fools)

5th century B.C.

 * Circa 450 B.C.: A crew of Greek sailors are taken from this time to participate in a boat race through the Solar system by a group of Eternals. (DW: Enlightenment)
 * Circa 400 B.C.: The Fourth Doctor brings Leela on a visit to Athens. (ST: The Brain of Socrates)

4th century B.C.

 * Circa 330 B.C.: The Doctor meets Alexander the Great. (DW: Robot)
 * Circa 300 B.C.: The First Doctor, Ian, and Barbara visit Alexandria during the reign of Ptolemy I. (VD: The Book of Shadows)

3rd century B.C.

 * Circa 218 B.C.: The Doctor meets Hannibal. (DW: Robot)

1st century B.C.

 * 69 B.C. - Cleopatra is born; she will take the throne of Egypt in 51 B.C. (known history)
 * Circa 40 B.C.: The Doctor learns swordsmanship from a captain in Cleopatra's bodyguard (DW: The Masque of Mandragora) Possibly he was romantically involved with the Egyptian queen for a while as well. (DW: The Girl in the Fireplace)
 * 30 B.C. - Suicide of Cleopatra. (known history)

Behind the scenes

 * An inherently Christian designation, BC is not generally used in calendars of the traditionally non-Christian world. Consequently, some people use BCE (meaning Before Common Era) for BC. CE (meaning Common Era) as a substitute for AD. These largely cosmetic replacements are thought to avoid religious offence. However, Doctor Who fiction has typically remained loyal to the BC/AD convention. Even as late as the RTD and Moffat eras, dialogue and on-screen graphics prefer the Christian convention. (DW: The Fires of Pompeii, The Pandorica Opens, A Good Man Goes to War)
 * In the real world, there is no year zero, so therefore 1 BC is immediately followed by 1 AD. Doctor Who fiction, however, is unclear as to this point.
 * On this wiki, templates and categories, both of which use, or are used in, mathematical formulae, assume the presence of a year zero, since the fiction of the DWU allows it. Hence, we deem that the year 2000 is in the 21st century.