The Torchwood Institute (or "Torchwood" for short) was an organisation founded in 1879 (TV:The New World) to protect the British Empire (laterGreat Britain) from extraterrestrial threat, to capture the Doctor (whom Queen Victoria regarded as one such threat) and to secure alien technology for Britain. (TV: Tooth and Claw, Army of Ghosts)
Torchwood had branches across the Empire. (TV:Everything Changes, AUDIO: Golden Age) Through2007, the leading branch was Torchwood One inLondon. (TV: Army of Ghosts) After the Battle of Canary Wharf, leadership moved to Torchwood Three in Cardiff, which already had a more ecumenical agenda of protecting the world sinceCaptain Jack Harkness had taken over in 2000. (TV:Doomsday, The Sound of Drums, Everything Changes, Fragments)