Jack "King" Kirby is one of the single most important people in comic book history. Unfortunately, many people still haven't heard of him. I hope to rectify that here.
What do The Fantastic Four, Uncanny X-Men, Hulk, Thor and Iron Man have in common?
You are correct if you said they are all Marvel comics. If you said they were all created by Stan Lee, you're only half right.
The legend goes...
Stan Lee would come up with ideas, basic outlines and tell them to Jack Kirby. Kirby would then go away and draw a comic book based on that idea. Once he was finished, he'd give the comic back to Lee who'd fill in the dialogue and speech as he saw fit. Often Lee would have no idea what he'd get back from Kirby and has been quoted as saying it was like doing a crossword puzzle, trying to figure out what story the pictures were telling him.
Later, the idea of credit became the subject of bad blood between Kirby and Marvel and, after his death, his family pursued the rights to their father's creations. Ultimately, the family settled out of court and Marvel does credit Kirby as co-creator for the books he worked on.
Aside from creating the bulk of what became the Marvel universe with Stan Lee, Kirby also created Captain America with Joe Simon. And, after moving to DC comics in the early 1970s, he also created The Fourth World which included the character of Darkseid (who is rumored to be the bad guy in the upcoming Justice League movie.)
Kirby's art style
Jack Kirby not only helped create many of the characters we know and love today, but he also created a new style of graphic storytelling that became the blueprint for Marvel artists and an exciting new visual chapter in comic books.
While Batman and Superman looked like this:
Kirby's legacy is undeniable. Both he and Stan Lee changed comic books forever and since we're still discussing many of the characters they co-created, it feels right that he is still celebrated today.