Lee was the creator or co-creator of iconic characters like the Fantastic Four, Spider-Man, Black Panther, the Incredible Hulk, X-Men, Iron Man, Daredevil, Ant-Man, Thor, and more. He excelled at creating not flawless saviors, but characters with depth. He’s known for co-founding the publishing company Marvel Comics with Jack Kirby in 1961.

According to THR, Lee died Monday morning at the Cedars-Sinai Medical Center in Los Angeles.

While Disney bought his publishing house for $4 billion in 2009, Lee stayed in the picture—literally. While not every superhero fan may read the comics, many still knew Lee for his cameos in the Marvel movies.

Lee was born on Dec. 28, 1922 to Romanian immigrants. He grew up in Washington Heights, and after graduating high school, Lee joined the WPA Federal Theatre Project. In 1939, he got a job as a gofer earning $8 a week at Timely Comics, the publisher that would eventually become Marvel.

In the past few years, Lee has made headlines not for his work, but for controversies. His wife of 69 years passed away in 2017. Not a year later, he filed a $1 billion lawsuit against POW! Entertainment, a company he co-founded in 2001, alleging it stole his likeness for financial gain. Within two months, however, Lee dropped the suit. THR reports Lee also sued his former business manager and filed a restraining order against a man who handled his affairs.

Despite the controversies of late, Lee will be remembered for the icons he created. Characters like Spider-Man taught young readers that even superheroes have anxieties, girl problems, and other relatable issues. He created a brand that has now outlasted its creators. As the man himself would say, “Excelsior!”