Alistair Gordon Lethbridge-Stewart (Unbound Universe)

Alistair Gordon Lethbridge-Stewart was a human, and former head of U.N.I.T.

Head of Unit
Alistair Gordon Lethbridge-Stewart was a military man, who was put in charge of U.N.I.T. when it was first formed. Combating various alien invasions, but often failing to stop them, U.N.I.T. was soon shut down. During his career, Alistair had to make many tough decisions, including sacrificing Mike Yates to stop the lizard invasion by sending a team back in time to bomb the creatures. However, the rest of the world saw his attempts to stop the Nestene,as a total failure, with the 'Plastic Purges' resulting in a national shortage.

Sympathy for the Devil
By the 1990s Alistair had moved to Hong Kong, and opened a bar called The Little England. It was there he met the Doctor again. After combating the Master, the Doctor invited Alistair to join him aboard the TARDIS, an offer of which he accepted. (NOTDWU: Sympathy for the Devil)

Masters of War
Alistair travelled with the Doctor for a while, until they landed on the planet Skaro. Befriending the Thals, Alistair played an essential part in stopping the Quatch invasion. Because he was reluctant to once again be a military leader, after the invasion was foiled, he chose to stay on Skaro as a peace mediator between the Daleks and the Thals. (NOTDWU: Masters of War)