Captain Marvel (DC Comics) abilities. Based on book sales, the character was the most popular superhero of the 1940s, outselling even Superman. Fawcett expanded the franchise to include other "Marvels", primarily Marvel Family associates Mary Marvel and Captain Marvel Jr., who can harness Billy's powers as well. Captain Marvel was also the first comic book superhero to be adapted into film, in a 1941 Republic Pictures serial titled "Adventures of Captain Marvel". Fawcett ceased publishing Captain Marvel-related comics in 1953, partly because of a copyright infringement suit from DC Comics, alleging that Captain Marvel was a copy of Superman. In 1972, DC licensed the
Excalibur (comic book) Excalibur (comic book) Excalibur is the name of several comic book titles featuring the team Excalibur and published by Marvel Comics, beginning with the original "Excalibur" comic book series which debuted in 1988. "Excalibur"<nowiki>'</nowiki>s original creative team, writer Chris Claremont and artist/co-writer Alan Davis, incorporated elements of two Marvel properties: the X-Men and Captain Britain. The resulting superhero team Excalibur first gathered together in "Excalibur Special Edition" #1 (1988) and were soon featured in a monthly series. Davis left with "Excalibur" #24 (1990) and Claremont with "Excalibur" #34 (1991), leaving a number of various plot points unresolved before his departure.