Science alive

Sir Alistair Gordon Lethbridge-Stewart, generally referred to simply as the Brigadier, is a fictional character in the British science fiction television series Doctor Who, created by writers Mervyn Haisman and Henry Lincoln and played by Nicholas Courtney. He is one of the founders of UNIT (United Nations Intelligence Taskforce, later Unified Intelligence Taskforce), an international organisation that defends Earth from alien threats, and serves as commander of the British contingent. Presented at first as reluctant to accept the continuing aid of the Doctor, over time the Brigadier became one of the Doctor's greatest friends and his principal ally in defending Earth. As one of the series' most prominent recurring characters over its history, the Brigadier appeared in 23 stories during the original run of Doctor Who, first appearing in the 1968 serial The Web of Fear opposite the Second Doctor (Patrick Troughton). The character made frequent appearances on the series following the introduction of the Third Doctor (Jon Pertwee) in 1970's Spearhead from Space.