"The Christmas Invasion" is a 60-minute special episode of the British science fiction television series Doctor Who, which was first broadcast on BBC One on 25 December 2005. This episode features the first full-episode appearance of David Tennant as the Tenth Doctor and is also the first specially produced Doctor Who Christmas special in the programme's history. In the episode, principally set in London, the alien race the Sycorax invade Earth, demanding that either humanity surrenders or one third of them will die.