Marvel held its own comic book convention, Marvelcon '75, in spring 1975, and promised a Marvelcon '76. At the 1975 event, Stan Lee used a Fantastic Four panel discussion to announce that Jack Kirby, the artist co-creator of most of Marvel's signature characters, was returning to Marvel after having left in 1970 to work for rival DC Comics. In <answer>October 1976</answer>, Marvel, which already licensed reprints in different countries, including the UK, created a superhero specifically for the British market. Captain Britain debuted exclusively in the UK, and later appeared in American comics.
When did Marvel's British-themed superhero first appear?
October 1976