Fox's Disney's purchase of Fox, it's worth noting what a debt the MCU owes to the X-Men. After all, it was the mutants who paved the way for the MCU and the modern day superhero movie golden age.

After the 1990s were dominated by Batman, in 2000, Marvel finally got into the blockbuster movie game with Bryan Singer's X-Men, which introduced the concept of mutants to moviegoers and made a star out of Hugh Jackman, who would go on to play X-Men: The Last Stand or Gavin Hood's X-Men Origins: Wolverine.

Related: Every Fox Marvel and X-Men Movie Ranked

Thankfully, Matthew Vaughn's 2011 reboot X-Men: Apocalypse. Now, the saga closes out with Simon Kinberg's Dark Phoenix and, with fans looking forward to the mutants taking their place in the MCU, the final Fox X-Men film feels like a lame duck.

Unlike the MCU, which boasts a string of billion-dollar blockbusters, X-Men has a strange legacy wherein its failures tend to overshadow its successes. But whenever an X-Men movie does hit the mark, it's usually spectacular: along with X2 and Days of Future Past, the spinoffs Logan were not only blockbusters but they broke new ground as R-rated superhero movies. Looking back on the last two decades of X-Men films, here's how they paved the way for the MCU, the mistakes they made and learned from along the way, and how the mutant franchise changed the superhero movie genre for the better:

The Original X-Men Trilogy Pioneered MCU Storytelling

Hugh Jackman as Wolverine and Anna Paquin as Rogue talking in X-Men

It was the X-Men franchise that brought the Marvel formula to the movies. Jean Grey's death in X2: X-Men United launched years of frenzied fan speculation about whether the next film would adapt Stan Lee cameos also began in X-Men.

One of the keys to Rogue and Logan first meet as he drives his truck through the Canadian winter. After warning him about what happens when she touches people, Rogue asked Logan if it hurts when his claws pop out and he replied, "Every time". This instantly communicated to the audience that having superpowers is sometimes tragic and that being "special" can also lead to pain, loss, and isolation.

Related: All Of The X-Men Movies In Chronological Order

Fox's X-Men Movies Have A Clear And Focused Theme To Explore

The Brotherhood of Mutants in X-Men The Last Stand

The X-Men movies have consistently communicated its central theme that mutants are a persecuted race hated and feared by humans. Charles Xavier's dream is that humans and mutants can co-exist, while Magneto feels mutants should assert their dominance over the world and homo sapiens. That core conflict, which has evolved through different permutations, has sustained the entire saga but it also allowed the audience to ask themselves who they would stand with and what their values are.

However, X-Men movies range from asking the biggest questions about the genocide of the entire mutant race, to deeply personal stories like trying to save Jean Grey from her darkest impulses being manifested by the gravely ill mentor Professor X and his 'daughter' Laura before he dies. All throughout the saga, mutants have been mistreated, enslaved, and weaponized as the X-Men movies hold up a mirror to abuses inflicted upon people in the real world. The X-Men still play into the superhero genre's tropes of costumes, superpowers, and saving the world from villains, but beneath the action-packed conflicts are persistent themes, difficult questions, and no easy answers, which makes X-Men movies a cut above other superhero flicks.

X-Men Went Places Other Franchises Wouldn't

Deadpool Logan X-23

Today, fans thrill to see the Avengers assemble but the X-Men brought the very concept of the superhero team to movies. Before X-Men, superhero movies were about a lone caped crusader defending one particular city and only Christopher Reeve's Superman was truly a global superhero. X-Men changed all of that with its very first scene depicting young Erik Lensherr's trauma in World War II Auschwitz. The movies' scope continued to grow, taking the X-Men to San Francisco in The Last Stand, before the X-Men movies started playing with alternate history: Logan, who was born in the 19th century, fought in both World Wars and Vietnam before taking on ninjas in Japan in the first two Wolverine spinoffs. X-Men: First Class depicted the Cuban Missile Crisis, Days of Future Past went from Russia and China in the future to the 1973 Paris Peace Accords, and by X-Men: Apocalypse, the story jumped from Poland to Egypt while nuclear missiles hovered over the entire world.

The X-Men movies also broke out of its own genre and began experimenting with R-rated material. Thanks to Logan was Oscar-nominated and inspired by classic Westerns like Shane, giving Hugh Jackman's Wolverine a poignant ending. Only in X-Men can fans thrill to see eleven-year-old Laura Kinney (Dafne Keen) violently hack and slash her enemies with her claws.

Related: How Dark Phoenix Connects To Days of Future Past's Ending

As for the mainline X-Men films, X-Men: First Class was a groovy 1960s international Cold War thriller that predated copy of X-Men: The Last Stand that aims to have more depth and dimension. Not to mention the brilliant Quicksilver superspeed sequences in Days of Future Past and X-Men: Apocalypse outshine everything Avengers: Age of Ultron did with the same character. In spite of their flaws, the X-Men movies deserve kudos for their willingness to boldly take chances instead of always sticking to convention and playing it safe.

X-Men's Timeline Isn't That Bad (And They Worked To Fix It)

X-Men First Class promo shot

It's certainly no secret that the X-Men movie timeline is a bewildering mess, but it can be generally understood if it's broken up into its two main components: the original trilogy timeline and the post-First Class reboot timeline. Yes, the bizarre choice to set each X-Men film after First Class a decade later makes the The Avengers.

To X-Men's credit, the First Class reboot was still successful and Days of Future Past was an ingenious reset that wiped X-Men: The Last Stand out of continuity. What's more, First Class' recasting addressed the advancing age of the original cast and breathed new life into the franchise; McAvoy and Fassbender successfully replaced Patrick Stewart and Ian McKellan as Xavier and Magneto while the franchise scored Jennifer Lawrence to play Mystique before she became one of Hollywood's biggest stars. The success X-Men had in recasting their characters is the blueprint for what the MCU will need to do when they inevitably have to recast Captain America, Iron Man, and Thor, not to mention recasting the X-Men for the third time when they debut in the MCU.

X-Men's Big Problem Was Inconsistency

Oscar Isaac in X-Men Apocalypse with Storm and Psylocke behind him

With the dominance and popularity of the MCU, the X-Men have struggled to compete in the marketplace that they helped usher in. Even though the X-Men franchise began in 2000, there have only been 12 Fox-produced X-Men movies (fewer X-Men movies but Marvel Studios maintains a high level of quality that consistently rewards fans' expectations whereas the X-Men movies are more of a crapshoot where it seems like the bad films outnumber the good ones. X-Men: Apocalypse even infamously contained an in-joke that "the third film is always the worst" that ended up as a meta-commentary on itself.

Related: Every Marvel Movie (2019 - 2021)

The Mystique's importance was increased so that Days of Future Past and X-Men: Apocalypse were both about her "coming home" to the X-Men. Meanwhile, other popular characters like Storm, Nightcrawler, Jubilee, and Psylocke have been grossly underutilized - this is something Marvel Studios will hopefully remedy.

Yet, despite the ways the franchise has come up short, X-Men can proudly boast its status as one of the most provocative and innovative superhero movie sagas that helped inspire the MCU's success - and it's better overall than its detractors will it. Dark Phoenix may mark the end of this incarnation of the X-Men but the mutants will one day rise again in the MCU. The new crop of X-Men will then have to overcome the shadow of Fox's X-Men and the unforgettable stories, characters, and moments they left behind.

Next: Every X-Men Movie Ranked, Worst to Best