Though Marvel Comics' Avengers and the X-Men debuted in the same month in 1963, interactions between the teams were not exactly plentiful in the years that followed despite both teams being a part of the publisher's revolutionary shared universe. It is a more recent development that the publisher's two premiere teams have become more and more intertwined with each other, with 2012's major Marvel event, "Avengers vs. X-Men," promising to be their biggest confrontation of all. With that in mind, CBR News takes a look at the history of the the ongoing relationship between the teams as a primer for those who might not be so familiar with their long history and a refresher for hardcore fans of Earth's Mightiest Heroes and mutantkind alike.
The first meeting between the two came very early in both teams' careers, as Iron Man used an image projector in "Avengers" #3 (published in January, 1964) to communicate with all the superheroes in the Marvel Universe, informing them he was looking for the Hulk and asking everyone to contact him if they encountered the green Goliath. Iron Man learned of the existence of the X-Men when Angel turned evil after exposure to radiation in "Tales of Suspense" #49 (which was published in the same month), leading the X-Men to try to enlist the Avengers' help in stopping (and then curing) Angel. Iron Man was the only Avenger available and, after facing off against Angel, he eventually caused the winged mutant to break free of the effects of the radiation. The X-Men were, naturally, quite grateful.
In "X-Men" #9, the two teams finally came face-to-face during a conflict with the villain Lucifer -- the same villain who was responsible for crippling Xavier. However, when the X-Men arrived on the scene of the fight, Xavier's students discover that Lucifer had connected a bomb to his own heartbeat. If Lucifer is killed -- or even physically harmed -- the bomb will go off. Despite this, Xavier devises a plan to stop Lucifer without risking an explosion -- and then, the Avengers appear. Thor's hammer detected Lucifer's presence and the heroes join the battle with the intent of stopping the villain, but Professor X orders his X-Men to hold the Avengers off to prevent the device from detonating. The two teams tussle for a time, with the X-Men holding their own, though the Avengers were clearly holding back. Eventually, Professor X is able to contact Thor telepathically and inform him of the situation, at which point the Avengers agree to leave the situation to the X-Men, allowing the confrontation to be resolved without incident.
For the next several years, interaction between the teams is minimal outside of both groups attending the wedding of Reed Richards and Sue Storm in 1965's "Fantastic Four Annual" #3. However, it is worth noting that Quicksilver and Scarlet Witch, two members of the recurring X-Men rival group, the Brotherhood of Evil Mutants, not only made the decision to become superheroes after an encounter with the X-Men in "X-Men" #11, with the mutant siblings eventually joining the Avengers in "Avengers" #16.
Unsurprisingly, Quicksilver and Scarlet Witch were once again the reason behind the next meeting of the two teams. After Scarlet Witch was accidentally wounded during a battle with Magneto in "Avengers" #49, her over-protective brother took her and re-joined Magneto's Brotherhood of Evil Mutants for her safety. Taking up residence on Magneto's personal island fortress, they quickly came into conflict with the X-Men, who were captured by Magneto's group in "X-Men" #43. In #44, Angel escaped and left the island in order to find help. In #45, Cyclops escaped and battled Quicksilver, at which point the speedster mutant's Avengers teammates show up. Angel had made his way to the Avengers, who were already looking for Quicksilver and Scarlet Witch themselves. However, during the course of their journey to the island, they discovered a listening device on Angel -- planted by Magneto in order to sow distrust. After restraining Angel in the Avengers' jet, the team was predisposed to distrusting the X-Men when they walked in to find Cyclops standing over an unconscious Quicksilver, leading to a fight between the teams. Cyclops escaped and freed his captured teammates, however, Magneto utilized mind-control technology to force the freed X-Men to fight against the Avengers. Angel, having escaped from the Avengers' restraints, showed up in time to destroy the mind-control device, ending the fight. The two teams combined forces to take out Magneto, but in the ensuing melee, Scarlet Witch and Quicksilver snuck away, breaking their ties with both the Brotherhood and the Avengers.
The next time the teams crossed paths was when the X-Men attend the wedding of Hank Pym and Janet Van Dyne in 1968's "Avengers" #60. Soon afterwards, the X-Men's ongoing series ceased publishing new stories due to the title's diminishing popularity, and the X-Men were in creative limbo.
Without a series of their own, the X-Men next met up with the Avengers years later in 1972's "Avengers" #110-111, a three-part storyline (with the middle chapter taking place in "Daredevil" #99) when the two teams combined forces once more against the evil power of Magneto, who had developed the ability to control people's minds through the iron in their brains. Hank McCoy, the X-Man known as Beast, had already left the X-Men by this point, having transformed into a blue, furry hero in the pages of his own feature in "Amazing Adventures."
1975 saw the release of "Giant-Sized X-Men" #1, the infamous introduction of the All-New, All-Different X-Men. This group of then-unfamiliar mutants saw little interaction with the rest of the Marvel Universe for a number of years. It was not until 1978's "X-Men" #111 that an Avenger had any sort of dealing with the X-Men -- and it was their former member, Hank McCoy, who had become an Avenger in 1975's "Avengers" #137. The Beast appeared in a few more X-Men stories over the next couple of years, including the "Dark Phoenix Saga," in which he played a significant role.
1981's "Avengers Annual" #10 featured the next major meeting between the two teams. Professor X was revealed to be old friends with Carol Danvers, the former Avenger known as Ms. Marvel. Carol had left Earth and the Avengers for the other-dimensional world known as Limbo with Marcus Immortus, a man she claimed to love, but the circumstances of their relationship seemed quite sketchy -- Immortus had plied Danvers with mind-control from Limbo and, since he could not be with her physically, magically impregnated her with himself so that he could have a corporeal form on Earth. After this, she decided to go to Limbo with him, the Avengers somehow being perfectly fine with the entire situation. After things fell apart in Limbo, Carol returned to Earth, only to have her powers (and her memories) ripped away by a new addition to the Brotherhood of Evil Mutants; Rogue! The X-Men took Carol in and, when the Avengers came to visit Carol at the X-Mansion (after the Avengers fought and defeated the Brotherhood of Evil Mutants), Carol tore into her former teammates for allowing her to leave for Limbo when she obviously wasn't in a frame of mind to make a proper decision for herself. She remained a guest of the X-Men for a while before gaining cosmic powers and joining the intergalactic team known as the Starjammers.
Colossus was one of a number of superheroes who was chosen to compete against the cosmic powerhouse known as the Champion in 1982's "Marvel Two-in-One Annual" #7, later appearing in the epilogue to that story in "Marvel Two-in-One" #96. Later that year, the X-Men were among the many superheroes featured in the "Contest of Champions" miniseries, along with a number of Avengers.
In 1984, members of the X-Men and Avengers were both heavily involved in" Marvel Super-Heroes: Secret Wars," a twelve-part series throwing all of Marvel's most prominent heroes and villains together. Even here, though all the heroes were stuck on the same planet together, the X-Men and the rest of the heroes tended to keep their distance from each other, with the separation actually being an explicit plot point. After returning to Earth, the X-Men joined with the Avengers -- and all the other heroes on Earth -- in final battle against the Dire Wraiths in 1985's "Rom" #65. During "Secret Wars II," the X-Men and the Avengers once more engaged in battle against the Beyonder, but even then, they tended to maintain a distance from each other.
The next major conflict between the two teams --and the largest until next year's event -- took place in the 1987 miniseries "X-Men versus the Avengers." The story, begun by Roger Stern and Marc Silvestri with Tom DeFalco and artist Keith Pollard contributing the final issue, featured the Avengers attempting to force Magneto to stand trial again in the World Court after an aborted trial in "Uncanny X-Men" #200. Magneto had recently been granted leadership of the X-Men in the aforementioned "Uncanny X-Men" #200 by an injured Professor X who subsequently left Earth to recuperate from injuries. Throughout the series, the two groups really don't do much in the way of fighting -- though this was different in Roger Stern's original plans for the series -- as other groups like the Soviet Super-Soldiers and the Mandarin come into play, giving the two teams common enemies to fight. The series ended with a truce between the groups as Magneto submits to another trial in front of the World Court, using mind control to guarantee he is not convicted of his crimes.
While individual members of the X-Men continued to have notable interactions with members of the Avengers or the team as a whole (like Wolverine and Captain America in "Captain America Annual" #8 and Cyclops and Professor X in "Avengers" #350), the next major meeting between the two teams was part of their joint 30th anniversary in 1993.
The crossover, known as "Blood Ties," was bookended in "Avengers" #368 and 369, with the middle chapters taking place in "X-Men" #26, "Avengers West Coast" #101 and "Uncanny X-Men" #307. The crossover dealt with the fall-out of the X-Men's own 30th Anniversary event, "Fatal Attractions," which came to a dramatic head in "X-Men" #25 (yes, they did in fact go from one crossover to a second crossover in a single issue), with Professor X mind-wiping Magneto. In "Blood Ties," Magneto's former Acolyte, Fabian Cortez, incited a civil war in the mutant nation of Genosha. To protect himself from attacks from his former mentor, Cortez (who does not know that Magneto has been incapacitated) kidnapped Magneto's granddaughter, Luna, daughter to Avengers member Crystal and X-Factor member Quicksilver (in the early 1980s, it was revealed that Magneto was Scarlet Witch and Quicksilver's father). Despite the United Nations forbidding their interference in the matter, a group of Avengers headed to Genosha with the aid of the X-Men. Meanwhile, Magneto's current protege (and de facto leader of Magneto's Acolytes), Exodus, decides to intervene to kill Cortez -- and also kill Luna, as her being "just" a human is an insult to Magneto's legacy. The Avengers and the X-Men manage to rescue Luna, but in the process, the Avengers sever their ties with the United Nations.
The X-Men and the Avengers next crossed paths during Jim Starlin's "Infinity" crossovers ("Infinity Gauntlet," "Infinity War" and "Infinity Crusade"), but their next major meeting was during the 1996 company-wide crossover known as "Onslaught." Years earlier, Xavier mind-wiped Magneto, resulting in Magneto's darkness attaching itself to Xavier. Slowly, this affected Xavier's own soul and, through a series of events, Xavier's dark side (mixed with Magneto) took on the form of the malevolent being known as Onslaught, a powerful entity who sought to destroy humans and mutantkind alike. In the final battle, the Hulk destroyed Onslaught's armor, releasing the pure, destructive psionic energy contained within. The Avengers, the Fantastic Four and a handful of other heroes (and even Doctor Doom!) sacrificed themselves to contain the energy enough for the X-Men to destroy it, saving the planet. A year or so later, it turned out that the heroes had been rescued by the power of Franklin Richards, son of Mr. Fantastic and the Invisible Woman. Franklin's mutant power had been able to create a "pocket universe" where he was able to transport the heroes after their seeming death. They returned to Earth and resumed their superhero adventures.
While the X-Men and the Avengers continued to have various small-scale interactions here and there over the next few years, it was not until 2005 that they next had a major meeting. As was typical of the teams' paths crossing, Magneto's family was once again the bridge between the groups' interaction. The Scarlet Witch had been driven insane and used her reality-altering powers to tear the Avengers apart, leading to the deaths of two of their veteran members, Hawkeye and the Witch's former husband, Vision. The Avengers disbanded in the wake of the tragedy, and Magneto showed up to spirit his daughter away to deal with her mental problems.
The Avengers later re-formed and, in a newsworthy move, added Wolverine, a long-time X-Man, to the team. Soon after the Avengers' regrouping, both teams decided that they had to do something about Scarlet Witch, who was far too powerful and unstable to simply leave under Magneto's care. the teams ended up traveling together to Magneto's home in Genosha, a country which was once was a haven for mutants, but had been almost entirely destroyed during Grant Morrison's "New X-Men." Quicksilver found about their mission and raced to his sister, compelling her to use her powers to make mutants the reigning class in the world. The fallout of this move was told in the miniseries titled "House of M." Eventually, a group of heroes realized what had happened and took the fight to Magneto. In the series' final battle, the mentally unstable Scarlet Witch uttered three powerful words: "No more mutants." The mutant population plummeted into less than 1,000 mutants worldwide, but otherwise, reality returned to normal.
Over the last six years, the X-Men have become increasingly isolated in the Marvel Universe, though Wolverine has continued to be involved with the Avengers. Even when the Marvel superheroes turned on each other in "Civil War," the X-Men remained mostly on the sidelines, maintaining a friendly relationship with Iron Man's pro-government side in order to keep their lives from being overly affected by the War's events and fallout. They were even granted their own government protective service to defend their reduced numbers. However, when a mutant baby was born, the X-Men were forced to give up that protection to go on the run in order to protect the child from all the forces conspiring against her (in doing so, they also gave up their East Coast mansion home base). Eventually, the time-traveling mutant known as Cable took the baby into the future to protect her.