In the early days of the revamped Marvel Comics, Thor was one of the flagship characters created by Jack Kirby and Stan Lee that helped propel the publisher to the top of the sales charts along with Fantastic Four, the Incredible Hulk and others. In multiple interviews given in his lifetime, Stan Lee often presented the creation of Thor as something that came from his mind in a stroke of inspiration, imparting his brilliant ideas to Jack Kirby, who drew what Smilin' Stan described. A little digging into this claim, however, shows the truth isn't as clear cut as Stan often told it, and strikes at the heart of one of his biggest character flaws.

Marvel's Thor first appeared in August 1962's Journey into Mystery #83, with creation credits believed to be Jack Kirby (penciler/plotter), Stan Lee (editor/plotter) and Larry Lieber (scripter). Jack Kirby would go on to write and pencil the Thor portion of Journey into Mystery with dialogue by Lieber and Robert Bernstein until issue #90 when he had to step back due to being too busy writing and drawing Fantastic Four, and working on Human Torch solo stories in Strange Tales and Iron Man in Tales of Suspense. Kirby would draw an occasional issue until he came back to the title on a more permanent basis with Journey into Mystery #101 in 1964. He would remain the co-writer and penciler of Thor until Thor #179 six years later when he left Marvel Comics for DC.

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Jack Kirby and Stan Lee have both given multiple interviews regarding the creation of Thor, many of which are collected in John Morrow's book Kirby & Lee: Stuf' Said! These interviews directly challenge the notion that Thor was the brainchild of Lee and that Kirby simply followed his directive. In fact, Kirby had a lifelong interest in mythology, and had even created multiple Thor stories decades before collaborating with Lee on Marvel's superheroes.

Stan Lee and Jack Kirby's Thor Comics

Lee and Kirby Thor (1)

One of the only times Stan Lee truly acknowledged Kirby's creative involvement in Thor's formation appeared in a March 1967 interview on New York’s WBAI-FM radio. “I always say that Jack is the greatest mythological creator in the world. When we kicked Thor around, and we came out with him... I thought he would just be another book. And I think that Jack has turned him into one of the greatest fictional characters there are." In the same interview Kirby said:

All through the years, certainly, I’ve had a kind of affection for any mythological type of character, and my conception of what they should look like. And here Stan gave me the opportunity to draw one, and I wasn’t going to draw back from really letting myself go. So I did... I gave the Norse characters twists that they never had in anybody’s imagination. And somehow it turned out to be a lot of fun, and I really enjoyed doing it.

Kirby's Early Thor Stories

The first time Jack Kirby would mention Thor in comic form was actually in the same comic where Captain America debuted. The classic 1941 comic Captain America Comics #1 (with the cover where Cap punched out Hitler) featured a backup that Kirby drew and co-wrote with Joe Simon called "Murder LTD," which featured Hurricane, who was the son of Thor. His next use of Thor would be in a story he entirely wrote and drew in 1942's Adventure Comics #75, in which "Sandman and Sandy battle a modern THOR in the adventure of the Villain from Valhalla." Another notable use of Thor was in a story Kirby wrote and drew for 1957's Tales of the Unexpected #16 called "The Magic Hammer." In a story that would foreshadow what was to come, "The Magic Hammer" follows a man who finds Thor's hammer and is granted miraculous powers, only to squander them for selfish purposes before the real Thor appears.

Related: DC's New Gods Were Originally Planned For Marvel's Thor

Looking at Jack Kirby's body of work, it's obvious that he held a lifelong passion for mythology, and proved incredibly deft at crafting his own, with worlds he created now coming to life in the MCU and DCEU. In a March 1985 interview in Comics Feature #34 Jack said:

I did a version of Thor for DC in the Fifties before I did him for Marvel. He had a red beard but he was a legendary figure, which I liked. I liked the figure of Thor at DC and I created Thor at Marvel because I was forever enamored of legends. I knew all about these legends which is why I knew about Balder, Heimdall, and Odin. I tried to update Thor and put him in a super-hero costume. He looked great in it and everybody loved him, but he was still Thor."

In 1990's The Comics Journal #134 Jack said, "I loved Thor because I loved legends. I’ve always loved legends. Stan Lee was the type of guy who would never know about Balder and who would never know about the rest of the characters. I had to build up that legend of Thor in the comics." In Neil Kirby's deposition in the 2010 Marvel Worldwide, Inc. v. Kirby lawsuit over character ownership rights, Jack's son stated, “My father was always very interested, he loved mythology, he loved studying religion and history, just knew all about it, his bookshelves were just loaded with that kind of stuff... we would have long discussions about it."

Lee Downplays Kirby's Contributions

Thor Kirby

In addition to Stan Lee long maintaining ownership to the idea of bringing Thor into the comics, he would increasingly diminish Kirby's role over the years through the guise of veiled praise. Lee's constant diminishing of Kirby's role in Marvel's success would turn a friendship into a bitter rivalry, with Kirby even basing a DC villain off of Stan. In a 1995 episode of Canadian science-fiction/comic book news show Anti-Gravity Room, Stan said on the creation of Thor:

We've already done a guy who's the strongest guy on earth, we've done people who can fly, we've done people who can burst into flame... what can we do that's different? Let's do a god! And he (Jack) said what are you talking about? And I said let's do one of the Norse gods, we'll call him Thor: God of Thunder! Well by the time I finished talking about it Jack had sketched almost the whole character you know? And it was amazing how fast he was, and it was as if he plucked these things right out of my mind, only he improved on em' because by the time I would see the drawing it was 100 times more dramatic even than what I was thinking of.

Related: Stan Lee and Jack Kirby's Original Black Panther Ideas Were Atrocious

Up until he passed away at age 95, Stan Lee maintained his version of Thor's creation, each time adding elements to the story to inflate his role as Thor's creator. In a 2018 interview with Stan Winston School, Stan Lee again recounted his revised version of Thor's creation. "Everybody knew the Roman gods and the Greek gods. I figured most people aren't that familiar with the Norse gods so I did a little reading about them, and it was fascinating. Thor and Odin, and Odin had one eye and all that. And Loki... And I love adjectives so it wasn't just Thor it was The Mighty Thor."

Stan Lee made a lot of amazing contributions to the comic industry, but one of his biggest flaws was "taking credit for anything that wasn't nailed down" as Stan himself said in one of his 1999 editions of Stan's Soapbox, and it's very possible that with repetition, Stan grew to believe his own stories. But in the case of Thor, and much of Marvel Comic's early work, the evidence points to Jack Kirby's involvement being much more substantial than Stan Lee admitted.

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Sources: Kirby & Lee: Stuf' Said!, Anti-Gravity Room, Stan Winston School