Disney’s $4 billion acquisition of Lucasfilm and its outrageously lucrative properties in October 2012 was almost inevitable. People attuned to geekdom shouldn’t have been surprised when the House of Mouse scooped up Star Wars, for Disney knew full well it could steer a multi-faceted franchise since buying Marvel for the same amount in 2009. The two mega-properties share more than just a common owner. Marvel and Star Wars have a long shared history, not as competition, but as a melting pot of pop mythology. Since 1977, Star Wars and Marvel have been in a sort of endless feedback loop, dancing around the same strategies to their gainful advantage.

When Star Wars came out, nobody gave it a fair shake. George Lucas’ seemingly bizarre space movie with giant growling sasquatches and robotic villains confused enough people at movie studio 20th Century Fox that it was a near miracle when they saw Star Wars begin making money, and then promptly become the highest grossing movie ever made at the time.

Those sasquatches (Wookiees) and robotic villains (Darth Vader) were now part of a world that audiences wanted to explore further. They went to see the movie over and over again, but it couldn’t satiate their interest in the adventures of Luke Skywalker and the complex galaxy of stories George Lucas created. Star Wars was a post-war homage to 1930s serials, themselves big-screen representations of the comic books Marvel would go on to create at the end of that decade. An interrelated world of criss-crossing characters is what Marvel used to become a comics powerhouse, and what Star Wars used to closely resemble the types of comic books put out by Marvel.

But by the late 1970s, Marvel was in a slump. It had cancelled 31 titles and was selling a mere 280,000 copies of Spider-Man comics, its most popular title. Comic panels looked drab with movies like Star Wars ruling the zeitgeist. To resuscitate itself, Marvel took an “If you you can’t beat ‘em, join ‘em” policy, and made a pitch to Lucasfilm to adapt Star Wars into comic book form. A six-issue run was approved, and it did gangbusters. The first issue alone sold more than a million copies — four times that of Spider-Man.

Marvel's 'Star Wars 1,' an adaptation that expanded Lucas' movie.

Kids ate the comics up because they gave readers a broader sense of the world George Lucas couldn’t put on screen. Luke’s life on Tatooine and his adventures against the Empire were shaded in within the pages of the comics, but after the first six issues (with the last one featuring the cheeky title “Is This the Final Chapter?”) Marvel went off on its own with Lucas-stipulated instructions not to mention Darth Vader or the relationship between Luke and Leia. He’d save that for The Empire Strikes Back.

Marvel's 'Star Wars 7: New Planets, New Perils! ' featuring a 1977 standalone story with Han Solo and Chewbacca.

The first new story was issue #7, which began with an original Han and Chewie-centric run explaining why Han hadn’t paid Jabba the Hutt in A New Hope. The original comic run continued on for nearly a decade, and ended with issue #107 in 1986. That was three whole years after the original movie trilogy ended with Return of the Jedi.

The popularity of Marvel’s Star Wars comics beefed up the main storyline into a universe, albeit one that would become all too confusing when the Star Wars Expanded Universe kicked off in the early 1990s. Without movies to guide the way, Star Wars became a confusing and nearly impenetrable multimedia web of parallel stories, universes, and characters — similar to the endless iterations and variations Marvel continued to churn out in its comics through the decade and into the new century. But by the time that rolled around, Lucas had wised up — for better or worse — and set out on creating a new trilogy of movie prequels, getting his galaxy back on track. The story of the earlier galaxy far, far away in the prequels ended with 2005’s Revenge of the Sith.

Marvel mostly began dabbling in movies in the latter half of the 20th century by licensing heroes out to other studios. Marvel licensed characters to Fox and watched from the sidelines, no doubt hungrily, as 2000’s X-Men launched the superhero movie craze. Marvel wouldn’t follow with its own big-screen adaptation of its own properties until 2008’s seminal Iron-Man, planting the seeds for the sprawling Marvel Cinematic Universe. Back then, much like Star Wars, it was a gamble few thought would work.

“If they can make appealing movies, I don‘t see any reason why they can’t be successful,” said a financial expert in the New York Times when Marvel’s big-screen independence was announced. Another person offered a contrasting expectation: “I don’t know that they come out ahead at the end of the day, even when you adjust for risk and the time it takes.”

Since Iron-Man, Marvel’s gamble on a broad, interlocking cinematic world of different heroes and stories has grossed more than $3.5 billion worldwide.

It was a strategy that Disney latched on to enough to get while the gettin’ was good. Disney began distributing Marvel movies with 2009’s The Avengers, now the fourth-highest-grossing movie ever.

Marvel Studios president Kevin Feige standing in front of the movies planned for the Marvel Cinematic Universe through 2018.

Around two years later Disney CEO Bob Iger began asking George Lucas if he would sell what basically amounted to his first born. The thought process was, adding Lucasfilm to Disney’s list of mini-companies like Pixar and Marvel would add, as Bloomberg Business described in a 2013 article about the acquisition, “reservoirs of franchise-worthy characters that can drive all of Disney’s businesses, from movies and television shows to theme parks, toys, and beyond.”

With that, the Marvel-ization of Star Wars had begun. The Expanded Universe was scrapped, and everything in the new Star Wars universe, beginning with J.J. Abrams’ The Force Awakens and continuing with Gareth Edwards’ standalone movie Rogue One, was now canon, just like the Marvel Cinematic Universe. As writer Adam Rogers put it in a recent Wired profile about the future of Star Wars: “Marvel prototyped the process; Lucasfilm is trying to industrialize it.” And it’s obvious when you think about it. In the seemingly endless Star Wars and Marvel feedback loop, Star Wars saved Marvel, and now Marvel is poised to save Star Wars. Who knows where the loop will go next.

Photos via Wookieepedia, Getty Images