The last of the great serial kings, he starred in six. He is most famous for being the first actor to play Superman on film. His first serial was Republic's "Daughter of Don Q" (1946). He helped a modern day descendant of Zorro prevent an unscrupulous lawyer from stealing her land.
Two years later he was playing one of our greatest cultural icons in Columbia's "Superman" (1948) preventing Carol Forman's Spider Lady from stealing the deadly Reducer Ray. That same year Republic had Alyn battling Forman again as she searched for a lost treasure that would enable her to build a criminal dynasty in "Federal Agents vs. Underworld Inc." (1948).
Alyn's next serial was Republic's "Radar Patrol vs. Spy King" (1950) where he fought spies trying to prevent him from building a defensive string of radar installations along the American/Mexican border. Columbia's "Atom Man vs. Superman" (1950) had Lex Luthor pretending to reform and battling Superman in disguise.
After the second Superman serial Alyn vowed never to play the character again, feeling the typecasting had hurt his career. He turned down the TV role that eventually went to George Reeves, preferring to relocate in New York and pursue roles on the stage and in local TV. Columbia did coax him back to make one last serial, "Blackhawk" (1952). He faced off against Carol Forman one last time in a story of cold war intrigue.
As time passed Alyn made his peace with his most famous role, making a cameo appearance in "Superman: the Movie" (1978) and titling his autobiography "A Job for Superman".