Battle of Battersea Power Station

The Battle of Battersea Power Station was a major battle between the Cybermen of Pete's World and the resistance group known as the Preachers as well as the Tenth Doctor and his companions.

It ended when the Doctor shutdown the Emotional inhibitor of all the Cybermen, causing them to explode. The the Cyber-Controler fell into the exploding power station, (TV: The Age of Steel) while the remaining Cybermen were then sealed in the factories. (TV: Doomsday) It would serve as the first major conflict of a war that would finally end at the Battle of Canary Wharf in the Doctor's world. (TV: Army of Ghosts / Doomsday)

Origins
In the parallel universe known as Pete's World, John Lumic became obsessed with immortality and thus began creating the Cybermen with the plan to eventually transform himself into one. A small resistance group known as the Preachers led by Ricky Smith rose up to combat him and his efforts while Pete Tyler acted as a loyal friend to Lumic but in reality recognised his insanity and sent information to the Preachers under the alias Gemini, believing them to be security forces. In order to create more Cybermen, Lumic would trick homeless people desperate for food into getting into lorries and then kidnap them to be Cyber-converted as they wouldn't be missed.

After the president refused to fund his work, Lumic intistee his plans for a war footing, using the pre built Cybermen to assassinate the president at Jackie's birthday party. (TV: Rise of the Cybermen) Once done, he had the ear pieces activated to control the residents of London to go to the power station to await conversion. (TV: The Age of Steel)