Excalibur is a Marvel Comics superhero group, an offshoot of the X-Men, usually based in the United Kingdom. Conceived by writer Chris Claremont and artist/co-writer Alan Davis, the original Excalibur first appeared in Excalibur: The Sword is Drawn (1987).
The first Excalibur consisted of the English superhero Captain Britain, his lover Meggan, and several onetime members of the X-Men and related mutant teams. An eponymous series featuring the team lasted from 1988 until 1998. Originally, it was a wacky series involving cross-dimensional travel that incorporated as many elements of Captain Britain’s mythos as it did the X-Men’s. It became a more typical X-Book in later years.
Between Excalibur’s disbandment and reformation, a short-lived, ongoing series entitled Excalibur chronicled the efforts of X-Men founder Charles Xavier and his former nemesis Magneto to rebuild the mutant homeland of Genosha. Aside from the name and the writer, it had no connection to the superhero team.