One of Marvel’s first super-groups, Stan Lee created the X-Men as a youthful counterpart to the full-grown heroes in the Avengers. With membership consisting of Scott Summers (Cyclops), Jean Grey (Marvel Girl), Warren Worthington III (Angel), and Hank McCoy (The Beast), the X-Men were students, enrolled in Professor Xavier’s School for Gifted Youngsters. The secret was that these youngsters were mutants. Their genetic structure was different than that of normal people, and they had been blessed with strange super-powers as a result. They were called the X-Men because of that “something X-tra” that each possessed.
Although reasonably popular in its early days, the original run of the X-Men had almost faded from existence when it was suddenly revitalized by the introduction of the “New X-Men” in Giant-Size X-Men #1. It then went on to become one of Marvel’s most successful titles.