The X-Men are a team of fictional superheroes appearing in American comic books published by Marvel Comics. Created by artist/co-writer Jack Kirby and writer Stan Lee, the characters first appeared in The X-Men #1 (September 1963) and formed one of the most recognizable and successful franchises of Marvel Comics, appearing in numerous books, television shows, films, and video games.

Professor X is the founder of Xavier's School for Gifted Youngsters at a location commonly called the X-Mansion, which recruits mutants from around the world. Located in Westchester County, New York, the X-Mansion is the home and training site of the X-Men. The founding five members of the X-Men who appear in The X-Men #1 (September 1963) are Angel (Archangel), Beast, Cyclops, Iceman, and Marvel Girl (Jean Grey); Professor X and Magneto also make their first appearances in The X-Men #1. Since then, dozens of mutants from various countries and diverse backgrounds have held membership as X-Men.

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