2150s Dalek invasion of Earth
During the second half of the 22nd century the Daleks invaded Earth and occupied it for about ten years.
Prelude
The first sign of the invasion came in 2157, when the Earth was bombarded with meteorites. Initialy it was thought that this was the result of a cosmic storm, but shortly after things had returned to normal, people started dying of a new plague, delivered by the Daleks through the meteorites.
The majority of the population of Africa, Asia and South America died before Humans could find a cure. (DW: The Dalek Invasion of Earth)
Some Humans were immune to the plague, because some time after visiting the occupied Earth The Doctor had spread a counter-virus causing immunity, to make sure that there would be humans left to help him.
At the same time the Earth was decimated by the plague the Daleks attacked a number of Human colonies, including Azure, Sifranos and Qartopholos, though at the time the identity of the attackers was not known. This was in order to make sure the Earth could not expect help from there.
Invasion
After six months, in 2158, the Daleks landed saucers with the command saucer led by a Black Dalek. The Daleks subjugated the Humans and converted the most intelligent into cybernetically-controlled slaves known as Robomen.
At some point, New York City was completely destroyed. London on the other hand, though one of the locations the Daleks landed was merely occupied and remained relatively intact.
Earth under Dalek rule
The Daleks held the Earth for about 10 years. During the occupation period small groups of human resistance fighters continued to exist.
Throughout this period the Daleks operated a blockade of the Solar system in order to prevent Earth's colonies from attempting to liberate their homeworld. The colonies experienced many problems from the occupation, as they were dependent, to a degree, on communication with and support from Earth. (NA: GodEngine, Lucifer Rising)
The Daleks commenced a mining operation in Bedfordshire in order to reach the Earth's magnetic core, replace it with a propulsion system, and turn the whole planet into a massive spacecraft. (DW: The Dalek Invasion of Earth)
Liberation and aftermath
In the late 2160s following announcement by the Daleks that they would destroy London a freedom fighter known as Dortmun who had been developing explosive bombs initiated an attack on the Daleks' saucer at the London helipad. The attack liberated several prisoners of the Daleks; the bombs however did not work effectively against the Daleks, leading to several casualties. Ian Chesterton who had accompanied the freedom fighters remained on the saucer as it travelled to Bedforshire.
Following the saucer attack the Doctor, his granddaughter Susan and some of the resistance fighters who had been based in London (who included David Campbell) travelled to the site of the Daleks' mining operation at Bedfordshire. Barbara Wright and Jenny also (independently) made their way to Bedfordshire, but were captured, however also assisted in the final destruction of the centre of Dalek operations on Earth. In the aftermath of this the Daleks withdrew from the planet. The Doctor's grand-daughter, Susan Foreman decided to remain in this time period with David. (DW: The Dalek Invasion of Earth)
- The exact year of the liberation was never stated, though an account that the Daleks had occupied the Earth for about 10 years would place it in 2167 or 2168. It would most definitely be after 2164, as The Doctor found a calendar from this year in an abandoned building in London.
Tortured by Davros to reveal to him the Daleks' past defeats, the Doctor recounted this invasion, with some inaccurate information, saying that the invasion happened in the year 2000 and that the magnetic properties of the Earth's core itself helped to defeat the Daleks, as well as the determination of human resistance fighters. (DW: Genesis of the Daleks)
Alternate timelines
In an alternate timeline, the Daleks also invaded Earth from the future after World War III, nuclear war involving many nations, which happened in the late 20th century. However, the temporal paradox that enabled the nuclear war to occur was resolved and the timeline annulled. (DW: Day of the Daleks)
Behind the Scenes
The non-canonical film Daleks' Invasion Earth 2150 A.D gives a somewhat different account of these events.
The invasion possibly occurred during an earlier period of Dalek history as the Daleks, at that point had receiver dishes built into their casings to receive broadcast power for their survival. Earlier Daleks had had to rely on static electricity in the floors of the Dalek City.