The Marvel Cinematic Universe officially got its start in 2008 with the release of Iron Man, but it didn’t really get going until Avengers dropped in 2012. The universe fully blew up with that film’s post-credits scene, which left everyone with the same question - who is Thanos? While long-time Marvel readers were instantly enthused at the prospect of Thanos vs. the Avengers, newer fans flocked to the internet to dig up all the facts about Thanos they could find. What they discovered, however, was one of the most complicated - yet compelling - villain backstories in all of comic book history.
Thanos was created by Mike Friedrich and Jim Starlin and made his debut in Iron Man #55, which was released in February of 1973. Since then, Thanos has moved on from his Earth-bound rivals to take on more cosmic pursuits, eventually becoming the “big bad” the Marvel Universe had been sorely lacking. By now, Marvel readers know that when Thanos shows up, something huge is about to go down.