The X-Men are a superhero team appearing in American comic books published by Marvel Comics. Created by artist/co-plotter Jack Kirby and writer/editor Stan Lee, the team first appearing in The X-Men #1 (September 1963). Although initially cancelled in 1970 due to low sales, following its 1975 revival and subsequent direction under writer Chris Claremont, it became one of the most recognizable and successful franchises of Marvel Comics. They have appeared in numerous books, television shows, the Disney's 20th Century Studios X-Men films, and video games. The X-Men title may refer to the superhero team itself, the eponymous comic series, or the broader franchise including various solo titles and team books such as the New Mutants, Excalibur, and X-Force.
In the Marvel Universe, mutants are humans who are born with a genetic trait called the X-gene which grants them natural superhuman abilities, generally manifesting during puberty. Due to their differences from the majority of humanity, mutants are subject to prejudice and discrimination; many X-Men stories feature social commentary on bigotry, justice, and other political themes. The X-Men have fought against a variety of enemies, including villainous mutants, human bigots, supervillains, mystical threats, extraterrestrials, and malevolent artificial intelligences. In most iterations of the team, they are led by their founder Charles "Professor X" Xavier, a powerful telepath who runs a school for mutant children out of his mansion in Westchester, New York, which secretly is also the headquarters of the X-Men. Their stories have frequently involved Magneto, a powerful mutant with control over magnetic fields, who is depicted as an old friend of and foil to Xavier, variously acting as an adversary or as an ally.
The current iteration of the official X-Men team is headquartered in the Treehouse, a Krakoan base in New York City, and the roster is voted on by their fellow mutants in elections held at periodic Hellfire Galas.