Byrne's earliest professional work was in 1975 for Charlton Comics, but he soon found regular work at Marvel Comics and in 1977 began pencilling Uncanny X-Men, which became a runaway success for Marvel. His other notable works include writing and illustrating the Fantastic Four and revamping DC Comics' flagship title Superman during the 1980s. In the 1990s Byrne went to Dark Horse Comics to produce his creator-owned title Next Men.