Originally known as Captain Britain, Brian Braddock is a fictional superhero that appears in American and British comic books published by Marvel Comics. He was initially published in Captain Britain Weekly #1 and was created in 1976 by writer Chris Claremont and artist Herb Trimpe, with additional contributions from Alan Moore and Alan Davis. At first, the character was just meant for the British comic book industry.

Endowed with extraordinary powers by the legendary magician Merlyn and his daughter Roma, Brian becomes Captain Britain, assigned to be the champion of the British Isles and its peoples, as well as the defender of Earth-616 as a member of the multiversal Captain Britain Corps. Following his corruption by Morgan le Fay, his twin sister Betsy reclaimed the mantle of Captain Britain, with Brian taking up the moniker Captain Avalon as defender of Avalon.