Today marks the fiftieth anniversary of the debut of the Guardians of the Galaxy. They first appeared in the comic Marvel Super Heroes #18. In the issue, a group comprised of Charlie-27, Martinex, Vance Astro, and Yondu to defeat the villainous Badoon, who have enslaved everyone on Charlie-27's planet, and band together to defend the universe as the Guardians of the Galaxy.
Sales on the issue were strong, but the team would not appear again for another five years. The team would not get their own series until 1976 with Marvel Presents. The team was set in the far distant future, though would occasionally interact with modern day characters thank to time travel. The series lasted until 1979 and not revived until 1989 to cash in on the popularity of the television series Star Trek: The Next Generation. The series was eventually cancelled once again in 1995. It was not until 2008 when Marvel published the cosmos-spanning Annihilation: Conquest series that Yondu reappeared in the Marvel Universe and inspired a new Guardians of the Galaxy team. Marvel eventually launched a new series based on the original team in 2014.
It is the team that Marvel fans are currently familiar with. The initial run of the new team saw poor sales and was short-lived. They appeared in just one episode of The Avengers: Earth's Mightiest Heroes. It wasn't until Marvel Studios made a live-action film that the team became truly popular, now appearing on their own animated series. The team made one more live-action film, with a third in development, and are integral to Avengers: Infinity War and Avengers: Endgame. This team made several appearances on Ultimate Spider-Man, Avengers Assemble, Hulk and the Agents of S.M.A.S.H., Marvel Disk Wars: The Avengers, and Spider-Man. They made an appearance in Marvel Super Hero Adventures: Frost Fight! and got their own animated special with Lego Marvel Super Heroes – Guardians of the Galaxy: The Thanos Threat.