Battle of Canary Wharf

"This is not war! This is pest control!"

- Dalek Sec.

The Battle of Canary Wharf was one of the major battles between Humans and aliens in Earth history.

Origins
The Battle of Canary Wharf had its roots in the escape of the Cult of Skaro and the Genesis Ark into the Void from the Last Great Time War. This caused a crack in the universe, allowing travel between dimensions more easily than should have been the case after the demise of the Time Lords. (DW: The Age of Steel, Doomsday)

Beginnings
"The sphere is not ours. The sphere broke down barriers between worlds, we only followed. Its origin is unknown."

- Cyber Leader.

From the crack in the universe, the Parallel Earth Cybermen were able to travel from their dimension into ours, and infiltrated the planet in the disguise as the benign ghosts of deceased Humans. (DW: Army of Ghosts)

After two months (three years in Parallel Earth time), the Cybermen suddenly appeared in their true form,occupying every landmass on the planet before breaking into houses and promising to upgrade all Humans, commanded by the new Cyber-Leader. (DW: Army of Ghosts/Doomsday, TW: Everything Changes)

Simultaneously, the Cult of Skaro had exited the Void Ship with the Genesis Ark. The Cult, led by Dalek Sec, extracted information from a member of staff from Torchwood 1, and proceeded to communicate with the Cybermen via Dalek Thay and declare war (or in Dalek Sec's words, "pest control"). (DW: Doomsday)

the battle was started because the cybermen wanted to join forces with the daleks and upgraded the universe but the daleks declined and the battle was started

The Battle
"Daleks, be warned. You have declared war upon the Cybermen."

- Cyber Leader.

After a skirmish (Humans versus Cybermen versus Daleks), the Cult traveled to the main room in Torchwood Tower (Canary Wharf), elevated outside above the roof, and opened the Genesis Ark, releasing millions of Daleks who, under Sec's command, proceeded to "exterminate all life-forms below", killing Human and Cyberman alike. (DW: Doomsday)

During the battle, the Cybermen began to convert Torchwood personnel, like Yvonne Hartman and Lisa Hallett in large numbers. (DW: Doomsday, it was thought that yvonne was pulled into the void TW: Cyberwoman) These were, at least in some cases, not full conversions, with the brain removed and put in a Cyber-shell, but partial conversions where the Cybermen built over the Human body beneath. (TW: Cyberwoman)

The Doctor and Rose Tyler opened the Void, sucking all the Daleks and Cybermen who had been in the Void back into it, and finally nearly sucking Rose herself in, but Pete Tyler teleported through the Void, grabbed her and teleported back to his parallel Earth where her parents, Jackie Tyler, that universe's version of her father, Pete, and Mickey Smith had decided to stay. The entire battle had lasted less than a day, but the Doctor commented that "so many" people died that day, and that the effects on Earth were devastating. (DW: Doomsday)

Aftermath
Afterwards, of Torchwood 1's 823 personnel, there were only 27 known survivors. 467 were dead, with the rest numbered missing. Humans converted into Cybermen using only materials from the main universe remained, unaffected by the Void and were interrogated and studied by the remaining Torchwood Institute personnel. (WEB: torchwood.org.uk) Between the active Torchwood 2 and 3 branches, there are only half a dozen remaining Torchwood staff. (DW: The Sound of Drums)

Lists of the dead and missing were compiled and made public. Among those officially declared dead was Rose Tyler (and, presumably, Jackie Tyler and Mickey Smith) (DW: Doomsday)

Members of Torchwood 3, acting on orders from Jack Harkness salvaged all of the alien technology from the ruins of Canary Wharf. (TW: Fragments)

Known Torchwood survivors included Lisa Hallett and Ianto Jones, although Hallett's survival, partially converted into a Cyberman, was not immediately known by anyone other than Jones (TW: Cyberwoman). Jones (presumably hiding Hallett) subsequently travelled to Cardiff where he eventually ingratiated himself into Jack Harkness' Torchwood 3. (TW: Fragments). Jones hid Hallett within a secret area of Torchwood 3 for months in hopes of eventually reversing her conversion, but was unsuccessful and she was eventually terminated, making her the last known victim of the battle (TW: Cyberwoman).

The governments of the Earth denied the battle had ever happened and blamed the reports on mass hallucination caused by terrorists polluting the water supply with psychotropic drugs. (TW: Everything Changes) And it appeared life on Earth returned to normal, although London would endure several more major high-profile incidents involving aliens in the coming months and years (DW: The Runaway Bride, Voyage of the Damned, Partners in Crime, The Sontaran Strategem/The Poison Sky, The Stolen Earth/Journey's End)

By 2012, it had become known as the Battle of Torchwood, and a publicly known event cited in news broadcasts. (DW: Fear Her)

Related later events
The Doctor later discovered that the Daleks of the Cult of Skaro had escaped the battle and had transported to 1930s New York City, where an attempt at creating a Dalek/Human hybrid was made (DW: Daleks in Manhattan/Evolution of the Daleks). The last known survivor of the Cult, Dalek Caan, driven insane by returning to the era of the Last Great Time War, would later orchestrate a scheme that saw Earth relocated to the Medusa Cascade and an attempt by Davros to detonate the reality bomb (DW: The Stolen Earth/Journey's End). as a product of this the Cybermen trapped in the void were released and travelled back to the victorian era.