The X-Men were originally founded by a young Charles Xavier and Raven Darkholme in the 1960's working in conjunction with a secret department of the government called "Division X". Xavier then brought in Erik Lensherr to help lead the team, which also consisted of Havok, Darwin, Beast and Banshee. The team came into conflict with another group of mutants called the Hellfire Club, who were vying for world domination. Following this, Erik and Charles' views regarding the path of the emerging mutant race diverged resulting in the end of their friendship. Erik, now going by the name "Magneto", and Darkholme left the X-Men to form the Brotherhood of Mutants.
Professor X saves a group of mutants, including Scott Summers, from Stryker's research lab.
Warned by Professor X, part of the team, Cyclops and Storm, goes North to save two mutants, Logan and Rogue, from an attack of The Brotherhood of Mutants' member Sabretooth. The enemy is defeated, and the two mutants are taken to the X-Mansion, where Xavier informs Wolverine of the plans of Magneto, who is believed to be after him. Logan enters the team, at least as long as he's safe from Magneto's plans.
When Rogue, deceived by Mystique, leaves the Xavier Institute, Wolverine goes after her, and Cyclops and Storm follow him at the train station. In here, the team has a clash with The Brotherhood, this time lead by Magneto himself, who defeats the X-Men and kidnaps Rogue, who was his real objective.
Using Senator Kelly's memory, Xavier is acknowledged of Magneto's plan: he intends to transfer his powers to Rogue and use her to activate his new machine, which can transform normal humans in mutants. Trying to locate Magneto, Xavier falls in a trap set by Mystique and enters a coma. Jean Grey uses Cerebro instead of him, and learns that The Brotherhood is on Liberty Island, wanting to use the machine on the world leaders gathered in there.
The X-Men reaches Liberty Island and have another fight with The Brotherhood, during which Wolverine defeats Mystique and Storm takes care of Toad. The entire team is later imprisoned by Magneto's powers, which bind them to the Liberty Statue. Only Wolverine manages to free himself, using his healing factor and stabbing himself in order to break the boundings. After defeating Sabretooth, Wolverine frees the rest of the team, and while Cyclops blasts Magneto, he, with the assistance of Storm and Jean, frees Rogue and destroy the machine.
After the mission at Liberty Island, Wolverine leaves the team in order to learn something about his past, following the advices of an awaken Professor X.
After an unuseful search at Alkali Lake, Wolverine comes back to Xavier Institute, where he joins once again the X-Men. Meanwhile, following the attempted assassination of the President of the United States, Xavier has tracked down the mutant responsible of it, and sends Storm and Jean Grey to take him. The two arrive in an abandoned church, where they find Kurt Wagner, the teleport responsible for the assault at the White House, who seems to have been brainwashed in some way and forced to do what he did by someone else.
Meanwhile, Professor X and Cyclops are captured by William Stryker, who, thanks to the informations taken with force by Magneto, attacks the X-Mansion and hunts down the students. Wolverine, along with Rogue, Bobby Drake and John Allerdyce, manages to escape the Institute after a brief confrontation with Stryker, who seems to know something about his past. The group reaches Drake's place, in which they are attacked by the police, warned by Bobby's brother. After a fight, in which Pyro almost kills the policemen, the X-Jet piloted by Jean and Storm arrives and takes them aboard. The plane is tracked down and attacked by military forces, which manage to shoot it down. The X-Men are then saved by Magneto, freed from his prison by Mystique: the two members of the Brotherhood offer the remaining X-Men an alliance, since their united powers may have a chance to defeat Stryker's army and free Xavier and the other mutants.
The two teams start an attack at Alkali Lake's base, forcing Stryker to try and escape. While Jean Grey fights a brainwashed Cyclops and Storm and Nightcrawler free the kidnapped students, Magneto reaches Dark Cerebro, in which Xavier is forced by Jason Stryker to kill all the mutants on the planet. Thanks to his helmet, Magneto is immune to Xavier's mental attack, and reprogram Dark Cerebro so that the telepath's attack hits humans instead of mutants, then leaves, and has a confrontation with Stryker, who's trying to escape the base, and chains him to a rock.
Storm and Nightcrawler then reach Dark Cerebro and manage to stop Mastermind and free Xavier. Meanwhile, after a fight with Deathstrike, Wolverine too confronts Stryker and refuses to free him in exchange on informations about his past, leaving him chained while the dump is collapsing. Pyro decides to leave the X-Men and to join Magneto's Brotherhood, and leaves with him and Mystique on a chopper.
The reunited team goes for the X-Jet, but problems with the engine put them at risk of being killed by the flod. Jean Grey leaves the jet and, using her powers, stops the water for a while and makes the jet take off, sacrifying herself to save the other teammembers.
Immediately after the Alkali Lake battle, Xavier and the X-Men reach the White House, and talk to the President who's about to make a speech about the mutant issue. Xavier gives him Stryker's files, so that he can see that the assassination was part of Stryker's plan, and leaves warning him that humans and mutants should work together to build peace, or else they'll end up destroying each other in a war.
After Jean's apparent death, the X-Men are almost disbanded: Cyclops has gone depressed and ignores his duties as both a teacher and a team leader, while Wolverine tries unsuccesfully to substitute him, and the atmosphere at the Institute is always tense and gloomy. Things get worse when Worthington Industries announce that a "Cure" for mutants has been found, occasion in which ex-team member Hank McCoy comes back to the X-Mansion to discuss the situation with his old mentor, Xavier.
Caught in grief, Cyclops leaves the Mansion alone and comes back to Alkali Lake, where, in rage, he blasts the water. Hitting the lake, surprisingly, he awakes Jean, who wasn't dead, but protected herself with a telekinetic cocoon. Anyway, the "old" Jean has been replaced by her murderous and almost all-powerful persona Phoenix, who kills Scott. Feeling the disappearing of Scott's mind from his perception, Xavier sends Storm and Wolverine to investigate. The two are clearly schocked in finding everything floating on the lake's shore and an unconscious Jean laying on the sand. Jean is taken back to the Institute, where it becomes clear that the Phoenix is now preminent: after knocking unconscious Wolverine, Jean leaves the Mansion and comes back to her childhood house.
Worried about her unlimited powers, Xavier, accompanied by Storm and Logan, reaches her to Grey's place, but in here he finds out that Magneto too has been acknowledged with Jean's resurrection and wants to make her join his newly refounded Brotherhood. While Xavier and Magneto confront Jean, both of them trying to recruit her in the respective teams, a battle occurs outside the house: Storm easily defeats Arclight and Quill, but is beaten by Callisto, while Wolverine is vanquished by the Juggernaut. During the battle, Jean becomes enraged and kills Xavier, almost destroying the whole house in the process. While Logan and Ororo mourn their mentor's death, Magneto takes Jean with him and leaves.
After Xavier's and Scott's death, Storm takes the lead of the X-Men, and decides to battle the Brotherhood, who plans to destroy Worthington Labs and stop the Cure. The team is joined by Beast and some of the students (Iceman, Shadowcat and Colossus). Once arrived on Alcatraz island, where the labs are located, the team joins the army in the fight against the Brotherhood: Storm finally gets rid of Callisto, Angel manages to save his father from the Omegas and Kitty stops the Juggernaut who was trying to kill Leech, the young mutant whose DNA is the source of the Cure. After a brief fight, Wolverine, Beast and Colossus manage to defeat Magneto, and they inject him with the Cure, depowering him. When the battle seems to be won, the Phoenix becomes enraged and starts destroying everything around her, buildings, vehicles and people. While everyone runs for his life, only Wolverine manages to go near her thanks to his healing factor and, after declaring his love for her, he kills her.
After Alcatraz battle, mutants are seen no more as monsters, and can live their life in peace. Beast leaves the X-Men and becomes the new USA ambassador to the United Nations, while Storm becomes the new headmistress of the Xavier Institute.
- That homosapiens are equal to mutants.
Division X mutants
The mutants identified by CIA's Division X using the abilities of Charles Xavier and Cerebro were not X-Men but their discovery led to the X-Men's formation following the Hellfire Club's attack on the government facility.
- Charles Xavier/Professor X
- Erik Lehnsherr/Magneto
- Sean Cassidy/Banshee
- Alex Summers/Havok
- Henry McCoy/Beast
- Raven Darkholme/Mystique
- Armando Muñoz/Darwin (Killed by Sebastian Shaw)
- Angel Salvadore (Joined the Hellfire Club)
The first generation of X-Men was formed after the Hellfire Club's attack on Division X forced the remaining mutants into hiding.
- Charles Xavier/Professor X
- Erik Lehnsherr/Magneto (Created the Brotherhood of Mutants)
- Moira MacTaggert (Left the team to return to the CIA)
- Sean Cassidy/Banshee
- Alex Summers/Havok
- Henry McCoy/Beast
- Raven Darkholme/Mystique (Joined the Brotherhood of Mutants)
More than thirty years after the team's formation, a contingent of mutants led by Xavier was still in existence without any of the original members still actively serving. However, Henry McCoy made a brief return to the team following the discovery of the cure for mutation.
- Charles Xavier/Professor X (Unknown)
- Scott Summers/Cyclops (Deceased)
- Jean Grey (Joined the Brotherhood of Mutants then was killed by Logan)
- Ororo Munroe/Storm
- Henry McCoy/Beast
- Marie/Rogue (Depowered)
- Robert Drake/Iceman
- Katherine Pryde/Shadowcat
- Peter Rasputin/Colossus
- Warren Worthington III/Angel
Allies and Enemies
- Nightcrawler - Ally
- The President - Ally
- The Brotherhood of Mutants - Enemies
- Robert Kelly - Enemy turned Ally
- Hellfire Club - Enemies
- William Stryker - Enemy
- Lady Deathstrike - Enemy
Behind the scenes
- There are some characters from the comics who was planned to be included in the movie team but didn't make it:
- Beast in the first and second movie (he was added only in the third one).
- Gambit in the third one (appeared in X-Men Origins: Wolverine as a loner).
- Nightcrawler in the third one (Alan Cumming declined since he suffered for the prostetics in the previous movie and didn't want to do that again for a minimal role).
- Angel in the second movie (appeared in the third one).
- Emma Frost in the third movie (she was added in X-Men: First Class and appeared as a villian.)