Stan Lee created mutants a year before he wrote the first X-Men comic. Everybody knows the origin story of the Uncanny X-Men. They burst onto the scene in 1963, with the five original X-Men – Cyclops, Angel, Iceman, the Beast, and Marvel Girl – facing Magneto, the Master of Magnetism. Sales weren't particularly good for the first series of X-Men, ultimately leading to a relaunch in 1975. This introduced more iconic new characters such as Storm and Colossus.

Surprisingly, though, Lee actually created the idea of mutants a full year before X-Men #1 was released. That also means technically Marvel was publishing stories about mutants long before even the Avengers had first assembled. The irony is that Lee himself forgot all about this, and it came as something of a surprise to him when the story was unearthed in the Marvel archives. This first mutant story was recently revisited by Battle of the Atom's Adam Reck, and it's one that will undoubtedly leave many X-Men fans taken aback.

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Marvel published Marvel Age #104 in 1991, a celebratory issue intended to help market the upcoming X-Men #1. While preparing this, editor Jim Salicrup discovered a long-forgotten short story by Stan Lee and Steve Ditko from Amazing Adult Fantasy #14. To his surprise, "The Man in the Sky!" told the story of a man named Tad Carter who discovered he possessed powers of telepathy and telekinesis. Tad initially intended to use his superhuman abilities for the betterment of mankind, but he was met only with prejudice. He was rescued from a mob by an unseen force, and a telepathic voice in his mind revealed he was a mutant and had been saved by his fellow mutants. They had created a secret, hidden community in which they hid from humanity while they waited for the human race to develop to the point where bigotry and prejudice had finally been put behind them.

Marvel first mutant The Man in the Sky

"The Man in the Sky!" was published in 1962, but it is striking how close it is to the mutants of the X-Men comics. The script toys with the idea mutants were not the next evolutionary step of the human race but were instead created due to elevated radiation levels resulting from nuclear tests. It's easy to forget that this was indeed Lee's original idea for the origin of mutants, which explains why the X-Men were sometimes referred to as the "Children of the Atom." What's more, early X-Men comics do indeed suggest Lee envisioned most mutants as possessing telepathic and telekinetic powers; early issues of X-Men saw Xavier pull off some infrequent telekinetic feats, while at one point Magneto went for a telepathic stroll. Notice the idea that humans hate and fear that which they do not understand; although this concept isn't seen in the first few issues of X-Men, it didn't take Lee long to introduce it, and it became the defining theme in the franchise.

For his part, Stan Lee actually forgot Amazing Adult Fantasy #14. As he reflected in an editorial in Marvel Age #104, Jim Salicrup's discovery took him by surprise. "The Man in the Sky!" feels as though it was intended to be the beginning of an ongoing story arc, but Amazing Adult Fantasy was discontinued and it was forgotten. It's probably a good thing because while there are enough thematic similarities between the short story and the Uncanny X-Men, they are also very different; in fact, the idea of a hidden society of superhumans sounds rather more like the Inhumans. Had Lee continued the story, or even remembered it, no doubt the X-Men would never have come to exist.

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