There was a time - within my own lifetime - when the fictional universes published by Marvel and DC Comics seemed to be moving along a slow but steady path of progress. It had begun during the Silver Age when characters would move beyond their original status quos: Peter Parker graduated high school; Reed Richards and Sue Storm were wed; Tony Stark received heart surgery. This also applied to characters who died or retired - many deaths and retirements were intended to be permanent; after all, there was no want for lack of new characters to take an old one's place.
It was also an age where certain creators were provincial over how their creations were used and it was considered a good thing to respect those creators' wishes - that you should not write Elektra unless Frank Miller approved, nor should you write Thanos without Jim Starlin's consent. It was in this age that young people who had grown up as fans of the Silver Age Marvel Comics were ascending to positions of power and influence over the line of comics, people such as Jim Shooter and Mark Gruenwald. There was an increasing attempt to pin down how the Marvel Universe fit together, what it's laws were. There was also a zealousness (particularly for Gruenwald) to "tidy up" the Marvel Universe, to eliminate characters and places which seemed extraneous to the universe's primary protagonists.
For instance, in a series of back-ups found in What If, Mark Gruenwald & Ralph Macchio rewrote the backstory of the Titans, changing them from descendants of the Greco-Roman gods into a branch of the Eternals (the Eternals were created by Jack Kirby in 1977, years after Thanos and the Titans). I don't know what Starlin made of this retcon - fortunately, there's no good reason to bring up the Titans' origins, not unless the Eternals of Earth are involved.
It was in 1977 that Jim Starlin began to wind down what he had created for Marvel. It began as simply an effort to clean up his unresolved plots from Warlock, but through the events of Avengers Annual #7 & Marvel Two-in-One Annual #2 (written & drawn by Starlin, inked by Joe Rubinstein), he wrote Adam Warlock, Gamora, Pip the Troll and Thanos out of the Marvel Universe. Proving he could be a gracious collaborator with Marvel's other writers, Starlin fashioned this two-part epic from an idea which Bill Mantlo & John Byrne introduced in Marvel Team=Up #55 - that there were other Soul Gems beyond the one Adam Warlock possessed. In this story, it is revealed there are six Soul Gems, all of which have been located by Thanos. Unable to steal Adam's gem, Thanos instead siphoned some of its power during the earlier battle with the Magus; siphoning from all six gems, Thanos places the combined power inside a massive synthetic gem, with which he intends to destroy all the stars in the galaxy so that Death (who spurned him at the end of the Cosmic Cube saga) will again love him.
The first part of the story stands on its own fairly well - Adam learns of Thanos' synthetic gem and the Avengers (plus Moondragon and Captain Marvel, who have prior links to Thanos) join forces with him. The second half is more awkward as Spider-Man and the Thing journey into space to aid the Avengers. Starlin attempted to suggest that Spider-Man had received his powers so that he would eventually be present to assist in Thanos' defeat, but clearly no one has ever bought into that - if there were a higher destiny for Spider-Man, it would surely appear in a story dealing with someone from his own rogue's gallery - and it would have to be the "last" Spider-Man story 'cause where do you go from there?
In the course of the two-parter, Gamora was beaten to the verge of death by Thanos and Pip was rendered comatose; Adam absorbed both into his Soul Gem. Warlock died after his battle with Thanos, meeting his past self in an exact replica of the scene in Warlock where Adam absorbed his future self's soul. Finally, Adam's spirit briefly emerged from the gem to turn Thanos into stone, a fittingly cruel state of affairs for a man who worshiped death.
In 1982, Starlin put his other Marvel cosmic hero to rest in the first Marvel Graphic Novel: The Death of Captain Marvel. In that story, Mar-Vell is revealed to have developed cancer from exposure to the nerve gas in Starlin's last issue. Mar-Vell dies an unglamorous death in his bed on Titan - but Thanos' spirit appears to Mar-Vell to challenge him to one last fight, believing his foe should have a heroic death. This appearance of Thanos points to where Starlin would take the character in the future - a sardonic ex-conqueror who bears some grudging admiration for his enemies.
And that was it - the end of Thanos! That same year, Marvel published a prestige limited series called Warlock which collected all of Starlin's Warlock stories, including the two-part finale in the annuals. In 1985, Marvel reprinted all of Starlin's Captain Marvel as The Life of Captain Marvel. The fact that Starlin's stories from the middle of the character's publishing history were considered "the life" of the hero said much about how highly Starlin's work was regarded and the Cosmic Cube epic has been reprinted more frequently than anything else in Mar-Vell's mostly-overlooked series.
Although Captain Marvel and Adam Warlock were gone, their names were still valuable IP to Marvel, who created new characters to fit the name - although neither had powers or origins in common with their predecessors. Roger Stern's Amazing Spider-Man saw a new female African-American Captain Marvel the same year Mar-Vell died and the new Warlock (along with his evil father Magus!) debuted in Chris Claremont's New Mutants in 1983. Marvel didn't overlook Drax the Destroyer either; although Starlin left Drax alive, someone clearly thought the character had no purpose in the Marvel Universe without Thanos, so he died in 1982 at the hands of his own daughter Moondragon (and writer Jim Shooter). However, Thanos' legacy was seen as something worth preserving as Roger Stern created the villain Nebula as Thanos' granddaughter, a new Avengers villain. Mar-Vell's cosmic mentor Eon went on to become mentor to Mark Gruenwald's Quasar (and Quasar inherited Mar-Vell's role as Protector of the Universe).
And Jim Starlin? All of his Marvel stories had been wrapped up. Starlin's focus shifted to his creator-owned property, Dreadstar. In time, he went to DC Comics to write another Darkseid-like villain with his creation Mongul, then finally Darkseid himself in Cosmic Odyssey and spent some time on Batman, where he created the KGBeast and killed off the Jason Todd version of Robin.
However, in 1990 Jim Starlin returned to Marvel Comics and his most famous creation was close behind...
Next Thursday: The Gloves Are on.