Dalek invasion of Earth

Across their history, the Daleks launched multiple invasions of Earth, with both the Time Lords and far future human historians being aware that the Daleks from various basetimes had made incursions throughout the planet's history. (PROSE: Dalek Combat Training Manual, Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)

The Eighth Doctor told Sam Jones that the Daleks had invaded Earth "several times" mostly long after her "era" (PROSE: War of the Daleks) of 1997. (PROSE: The Eight Doctors) Scrutinising Dalek history during the Last Great Time War, the Time Lords' interest in their attempts to invade Earth was such that a whole section of their Dalek Combat Training Manual was dedicated to covering it. (PROSE: Dalek Combat Training Manual)

Origins
Home planet of the humans, the planet Earth was known to have long held an attraction to the Daleks, with the roots of this fascination being the cause of great debate amongst historians. Some claim that the Daleks were drawn to Earth because of its similarity to their homeworld of Skaro and the lush, thriving ecosystem that flourished there before the devastation wrought by the Thousand Year War with the Thals. Others argued for a more deep-rooted, psychological cause – that the humans of Earth reminded the Daleks of their humanoid forebears, the Kaleds; as such, the Daleks sought to exterminate them, as the fledgling Daleks had eradicated the Kaleds.

Yet others suggested that the interest in Earth stemmed from nothing more than simple military strategy, or else the Daleks' desire to claim the planet's rich resources for their ongoing war efforts; the Daleks' development of time travel technology would allow them to see the First Great and Bountiful Human Empire encompass numerous worlds in the future, with the Daleks consequently identifying the human race as a grave threat to their dominance of the universe and their self-appointed superiority over all other life form.

There was also cause to believe that that Renegade Time Lord known as the Doctor was inadvertently responsible for bringing humans to the attention to the Daleks. Indeed, the fragmentary legends of the Thals recorded that the fledgling Daleks were first introduced to humans in the form of Sarah Jane Smith and Harry Sullivan, companions of the Fourth Doctor who were briefly captured and interrogated during the Genesis Incident. This impressed upon the Daleks the existence of life beyond Skaro, in turn both kickstarting the Daleks' own space program and providing them with an early target for their uninhibited aggression. Furthermore, the Doctor's own patronisation of Earth led to a number of incidents involving Dalek forces visiting the planet at various points throughout human history, in order to pursue the Doctor such as during the Mechonoid Incident and the Time Destructor Incident, pursuit of the Doctor himself; in the Shoreditch Incident the Daleks came to Earth in an attempt to acquire the Hand of Omega, which had been left there by the Doctor. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)

Early history
The Time Lords also understood that the Daleks had long shown an interest in the planet Earth. They believed that the creation of the Daleks, which they failed to prevent, occurred concurrent to Earth's ancient history. (PROSE: Dalek Combat Training Manual) In their Dalek Combat Training Manual, they wrote that the first Daleks to leave their homeworld of Skaro were reconnaissance scouts, one of whom arrived on Earth in the 9th century, where it was defeated before being revived and becoming embroiled in the Recon Scout Incident of 2019 and the Security Drone Incident of 2021, during which it was finally destroyed. (PROSE: Dalek Combat Training Manual, TV: Resolution, Revolution of the Daleks)

The first invasion

 * Main article: 2150s Dalek invasion of Earth

Aftermath of the first invasion
Three decades following the first invasion, the Daleks launched a second invasion of Earth whilst being guided by the time-displaced Dalek Time Controller and aided by. The Daleks successfully occupied Earth again and planned to install a time engine to turn the planet in a plague world for Viyran viruses. This plan was foiled when Lucie Miller crashed a saucer into the engine, creating a time warp which wiped out the Dalek forces on Earth. (AUDIO: Lucie Miller, To the Death)

In the post-Time War universe, following the Siege of Trenzalore, "some" historians believed in the story of the Daleks' second 22nd century invasion. In any case, Earth eventually flourished in the aftermath, with humanity finally heading out to the stars to establish its own Empire. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)

Another invasion was to be launched in 2223 but was postponed after a Supreme's attempt to establish a forward base in London met resistance from. (AUDIO: Vengeance)

In what may have just been a simulation created by the energies of the Land of Fiction, (PROSE: Head Games) Davros and the current Dalek Emperor launched an invasion of Earth in 2254 after the former had stolen the sacred Time Ring from Gallifrey. This invasion was repelled by the Seventh Doctor, killing the Emperor, and the Time Lords froze Davros in time as punishment. (GAME: Dalek Attack)

An invasion of Earth in the 20th century was planned by the Daleks but abandoned due to the intervention of the Third Doctor. (COMIC: The Disintegrator)

Later history
The Time Lords understood that two Dalek plots to invade the galaxy of Mutter's Spiral, Operation Divide and Conquer in 2540, and the Daleks' master plan in the 40th century, were a means to enslave humanity. (PROSE: Dalek Combat Training Manual)

In the later stages of the Second Dalek War, Dalek time-travel theory stated that mastery of time travel would begin with the destruction of the Time Lords and end with the subjugation of humanity. (PROSE: Prisoner of the Daleks)

As both Gordon Lowery and Marc Cory understood in the year 4000, the Daleks had invaded Earth a thousand years prior before they disappeared from human space. (TV: Mission to the Unknown) By another account, Lowery stated that every schoolkid knew that the Daleks invaded Earth "a couple of times, and were beaten back", with not much having been heard about them since the Movellan Wars a thousand years prior. (PROSE: Mission to the Unknown)

By one account, a new Dalek invasion of Earth was led by Davros following the Shoreditch Incident and the destruction of Skaro. (AUDIO: Terror Firma)

The Time Lords indicated that, following the 22nd century invasion, another overt Dalek invasion of Earth would not come until the Bad Wolf Incident in 200,100. (PROSE: Dalek Combat Training Manual)

Undated events
The Dalek invasion of Tuvalu was an incident which the Eighth Doctor recalled having thwarted with Sam Jones. (PROSE: Unnatural History)

Behind the scenes
"2075 AD. And the Daleks have invaded Earth once more. Using their mighty Saucer ships they bombard London driving the surviving population underground. Once they land, the Daleks patrol the ground looking for survivors in the rubble to either exterminate or transform into their puppets using Dalek nanocloud technology. In the skies the Daleks use long range "Hoverbout" anti-gravity disks to pursue the resistance. The TARDIS materialises near to a Trans-Sys matter transmission station in Hyde Park and the Doctor realises that he will need all his resources to once again defeat his oldest enemies and save the Earth from destruction. The future of the human race hangs in the balance."
 * The Dalek Handbook states that, long after the 26th century conflict and the Exxilon Gambit, the Dalek Wars ended with another short-lived invasion of Earth (following the 2150s Dalek invasion of Earth) around the year 3000, after which humanity saw little to no Dalek activity for 500 years.
 * Character Options' Dalek Invasion Time Zone Playset depicted an invasion of Earth by bronze Daleks in the year 2075.

- Character Options