The War of the Worlds
The War of the Worlds, a 1898 novel by H.G. Wells, described the invasion of Earth by Martians using three legged war machines or "tripods".
Wells' experiences of witnessing interplanetary war alongside the Doctor may have vaguely inspired his novel. (DW: Timelash)
The Master is seen reading The War of the Worlds while holding the Doctor and Jo prisoner (DW: Frontier in Space).
Orson Welles' 1938 Halloween broadcast of a radio play adaptation The War of the Worlds convinced certain members of the American population that Mars had reallly invaded. (BFA: Invaders from Mars)
In the Land of Fiction, the Master materialized tripods in order to use heat rays against his enemies. (DWM: Character Assasins)
Behind the Scenes
Wells' The War of the Worlds, the first major novel of alien invasion and possibly the first to try to realistically envision alien life, inspired future science fiction to a great degree, up to and including Doctor Who. The Daleks have a certain similiartity to Wells' Martians.