Excalibur is a superhero group appearing in American comic books published by Marvel Comics. They are depicted as an offshoot of the X-Men, usually based in the United Kingdom. Conceived by writer Chris Claremont and artist/co-writer Alan Davis, they first appeared in Excalibur Special Edition #1 (1987), also known as Excalibur: The Sword is Drawn. Stories involving this team have featured elements of both the X-Men and Captain Britain franchises, frequently involving cross-dimensional travel.

Brian Braddock is a superhero appearing in British and American comic books published by Marvel Comics. Created in 1976 by writer Chris Claremont and artist Herb Trimpe, with later contributions from Alan Moore and Alan Davis, he first appeared in Captain Britain Weekly #1. He is the first character in publication to use the Captain Britain moniker, later adopting the title Captain Avalon.