Stan Lee, the Marvel Comics legend who co-created some of its most famous heroes like Spider-Man, Iron Man, and the Fantastic Four, died Monday in Los Angeles at the age of 95. Lee was reportedly rushed to Cedars-Sinai Medical Center where he later died, according to TMZ. The cause of death has not been immediately released.

Lee’s legacy is defined by his numerous popular comic book character creations for Marvel Comics, where he began working in 1939 when the company was called Timely Comics. The company changed its name to Marvel Comics in 1961 when Lee and artist Jack Kirby co-created the Fantastic Four and saw it go on to become a hit.

Every Major Comic Character Stan Lee Helped Create 74 IMAGES

Lee’s birth name was “Stanley Martin Lieber,” but used “Stan Lee” as his pen name and then later had it legally changed.

With the success of Marvel’s First Family came more Lee/Kirby creations throughout the 1960s, including Hulk, Thor, Iron Man and the X-Men. Lee co-created Daredevil with Bill Everett, and Doctor Strange and Spider-Man with Steve Ditko. The characters all lived in a shared universe that mirrors our own, with most heroes residing in Lee’s home of New York City. The common factor that proved to be Lee’s key to success was giving superheroes relatable flaws as opposed to making them perfect, infallible beings.

These characters eventually went on to star in lucrative movies, TV shows, and video games, and were the basis for action figures, statues, and all manner of merchandise. They are the foundation of Marvel Entertainment, which is now a multi-faceted company of which Marvel Comics is only one aspect of the business. Marvel Comics is currently the leading publisher of the comic book industry in terms of sales and comics sold and is only rivaled by fellow superhero publisher DC Entertainment. While Marvel eventually grew beyond Lee, many credit his showmanship as a large reason for the company’s initial growth and success.

Lee prided himself on having a friendly rapport with fans and would answer questions in the letters pages with a personable and exuberant style, signing his correspondences with his signature phrase, “Excelsior!”

Yet for as beloved as Lee went on to become as the smiling and affable “Stan the Man,” his career was not without controversy. Lee is credited with creating the “Marvel Method” of writing comics where he would write a summary of the story and let the artist draw the full issue from that rather than providing them with a fully scripted, beat-by-beat breakdown. This meant the artist was doing the lion’s share of the creative legwork, and so Lee was seen as taking an undue amount of credit over his artistic collaborators, Kirby in particular. In 1971, Kirby even created a comic character based on Lee called the Funky Flashman who was a money-hungry man that took advantage of others and tricked people into thinking he was making creative contributions.

Lee rose through the ranks at Marvel, holding positions as writer, editor, film executive producer, editor-in-chief, publisher, and chairman. Since moving on from Marvel, he has remained in the public eye largely thanks to the success of Marvel’s movies where he is listed as executive producer and can be spotted in many obvious-yet-endearing cameos. Such was Stan’s lovable fandom that it wouldn’t be uncommon for fans to applaud in the movie theater when he makes his brief on-screen appearances. He’s also made appearances in various comics, TV shows, and video games, ones made by Marvel and otherwise.

Lee has used his name to start new companies like Stan Lee Media and POW! Entertainment that made their own multimedia superhero franchises, although none ever took off in popularity like his early Marvel work. In 2011, Lee started his own comic convention called Comikaze Expo and was eventually renamed to Stan Lee's LA Comic Con.

Propelled by his massively popular and influential work at Marvel, Lee became an icon known across the world thanks to his glowing personality, sharp wit, and warm sense of humor, instantly recognizable in his signature aviators tightly trimmed mustache. His work also inspired multiple generations of comic book creators to pick up a pencil and start their own careers.

His wife Joan passed away in 2017 due to stroke-related complications. He is survived by his daughter Joan Celia "J. C." Lee.