The Ultimate Vampire Resource and Directory

The team's name is a reference to the "X factor", an unknown gene that causes mutant evolution. Co-creator Stan Lee recalled in his book Son of Origins of Marvel Comics that he devised the series' title after Marvel publisher Martin Goodman turned down the initial name which originally referred to "Xtra Powers", "The Mutants." In addition to this "official" explanation, the X-Men are widely regarded, within the Marvel Universe (as well as by the readers of the series), to have been named after Xavier himself. In Uncanny X-Men #309, Xavier claims that the name "X-Men" was never sought out to be a self-tribute. This lends credence to the statement Xavier made in Uncanny X-Men #1, in which Xavier stated he called the team X-Men "for ex-tra power!"

The X-Men were founded by the paraplegic telepath Professor Charles Xavier a.k.a. Professor X. Xavier gathered the X-Men under the cover of Professor Xavier's School for Gifted Youngsters at a large country estate at 1407 Graymalkin Lane in Salem Center, a small town in Westchester County, New York. The original X-Men consisted of five teenagers, each of whom the professor taught to control their powers: Angel/Warren Worthington III, Beast/Hank McCoy, Cyclops/Scott Summers, Iceman/Bobby Drake, and Marvel Girl/Jean Grey.