During the trial of Magneto, Professor X was severely injured and dying in Magneto's arms. Professor X asked Magneto to take his place as headmaster of Xavier's school. Professor X was then transported to a Shi'ar ship with Lilandra where the Shi'ar's medical technology could save the Professor. The Shi'ar ship was required to return to its own galaxy with no definitive date of the Professor's return. During this time, Jean Grey was revealed to be alive and had never been the Phoenix. The Jean Grey who became the Phoenix and died on the moon was a clone created by the Phoenix Force.
After the trial of Magneto, Cyclops was forced to relinquish his role as team leader of the X-Men to Storm. Despite the birth of his son, Nathan Summers, Cyclops' mistrust and doubts about Magneto distracted him from his personal responsibilities. When the rest of the original X-Men learned about Magneto as headmaster of Xavier's school, all five finally came together to meet especially anxious to see Jean Grey alive as well.
They did not trust Magneto to lead the X-Men and had doubts about his story concerning Professor X's whereabouts who may be dead. Since they mistrusted their former arch-nemesis, they created a group consisting of the original X-Men. Warren Worthington used his company to create the X-Factor group, where they posed as mutant-hunting humans at the urging of Warren's longtime friend Cameron Hodge. They also posed as human-hating mutants under the alias X-terminators.
Bob Layton and Jackson Guice were the creative team for X-Factor vol 1 #1 (2/1986) that brought the original X-Men back together. Joe Rubinstein also inked some of the art in this issue. Five years later, Peter David and Larry Stroman were the creative team for X-Factor vol 1 #71 (10/1991) that brought established allies of the X-Men together as a reformatted X-Factor team sanctioned by a branch of the US government. Al Milgrom was the inker for this issue.
X-Factor rescued many mutants like Rictor, Boom Boom, Rusty, Skids, and Artie. Beast was kidnapped by the scientist Carl Maddicks, and, in an attempt to "cure" him, Maddicks changed his appearance back to before he grew his fur. During one of their first battles, they came into conflict with Apocalypse and his band of mutant outlaws. They were one of the teams fighting against the Marauders during the Mutant Massacre in the Morlock Tunnels; it was at this time that Angel sacrificed himself to save a number of mutants and ended up losing his wings. Extremely depressed over the loss, Warren then escaped from the hospital and attempted to commit suicide, but was saved at the last second by Apocalypse so that he could become the Horseman of Death.
After the Massacre, Scott traveled to Alaska to find his wife Madelyne and their son Nathan, but could not do so; even the neighbors claimed to have no idea who he was talking about. During a battle with the Horsemen of Apocalypse, Beast was touched by Pestilence; his mutant physiology reacted by allowing him to become stronger at the cost of his intelligence, which was later restored, along with his fur, by Infectia. Madelyne returned as the Goblin Queen after selling her soul to the demon Sym; she used her new found powers to warp the city of New York and tried to sacrifice her son to get revenge against Scott for leaving her, but she died in battle against Jean Grey before she could kill him. After being attacked by the Magistrates, they traveled to Genosha during the X-tinction Agenda. While there, they fought alongside the X-Men against a robotic Cameron Hodge, the Magistrates, and Scott's brainwashed younger brother Havok. When they finished the fight and returned to New York, they battled Apocalypse and Scott's son Nathan was infected with the techno-organic virus; in order to save Nathan, Scott sent him into the future. The original X-Factor members eventually rejoined the X-Men after Professor X returned from space.
The Government Team
A US government agency led by Havok later took on the name X-Factor. This new team consisted of Polaris, Wolfsbane, Strong Guy, Multiple Man, and Quicksilver and their government human handler Valerie Cooper. Before the team is even officially came together Mister Sinister set a plan in motion to destroy them with the help of a US senator and his new team the Nasty Boys. They are sent by the government to help a dictator named Farnoq Dahn destroy a rebel force aided by the Hulk and the Pantheon in Trans-Sabal.
After they battle the Hulk and Havok is knocked unconscious, he is taken by Farnoq Dahn and turned in to a living nuclear bomb so he can take over the world. Hulk and X-Factor team up to take him down and force Farnoq Dahn to face his people. Unfortunately most people still believe that he is a god so Rick Jones takes control of a S.H.I.E.L.D. Mandroid and shoots him. When the group travels to Genosha, Madrox is infected with the Legacy Virus which causes his dupes to behave erratically and it eventually results in his death.
The team goes through many changes through the years. Havok is kidnapped and brainwashed for a bit and even once its broken stays with the Brotherhood. Strong Guy has a heart attack and Wolfsbane quits. Polaris goes through a dark period in her life and relationship. Newer members that came included Forge, Wildchild, Mystique, Sabretooth, Shard ( Bishop's holographic sister from the future), and XSE refugees Archer, Fixx, and Greystone.
With money accumulated from game-show winnings, Madrox started up a private investigation firm in Mutant Town with Wolfsbane and Strong Guy. Originally calling his company XXX Investigations, the group settled on the name X-Factor Investigations after the team they were formerly members of. Jamie also hired Siryn and M, who were former teammates of his during his time with Paris branch of X-Corporation.
After M-Day the majority of the inhabitants of mutant town lost their powers. Rictor was one of the depowered mutants and after considering suicide (with help from one of Jamie's dupes) was convinced to join X-Factor with the others.
The cryptic child Layla Miller ended up spending a lot of time at X-Factor Investigations, often irritating and confusing the occupants. Layla continued to hang out with X-Factor, subtly influencing the members actions with the stuff she knows. Learning more about her life as an orphan, she was invited to live with the team.
The team has since encountered a deranged depowered mutant named Doctor Leery, Damian Tryp and his rival investigation firm Singularity Investigations, the Isolationist, mercenaries Clay and Solo, depowered mutant terrorist group X-Cell (including the Blob and Marrow), and most recently Silver Age X-Men villain Arcade. The team has also notably been rivals with former teammate Quicksilver who has often tried to repower the depowered mutants with ineffective and often disastrous results.
X-Factor has also experienced internal friction after a drunken Multiple Man created dupes that slept with both Monet and Siryn. At first the two girls stopped speaking to each other, but the pair then became frequent partners and best friends.
After X-Factor Investigations disbanded, Harrison Snow, the CEO and President of Serval Industries purchased the X-Factor name from Madrox and recruited Polaris to start a new incarnation of the team to help people in the companies name. Polaris first recruits Gambit by tracking him down after a disagreement with Wolverine. Quicksilver signs up soon after, following his half-sister to Serval Industries and being invited to the team by Harrison Snow due to his previous Avenger status.
Major Story Arcs
Although often non-combatant rivals with the X-Men, X-Factor Investigations were recruited to participate in the fight for the first new mutant baby which launched Messiah Complex.
Madrox agreed to send two dupes of his to the future (with the help of Forge) to gain information about the future. Layla hitched a ride on the device and became stuck in the future. Unbeknown to Madrox, there was no way in retrieving the dupes and Cyclops and Forge had intended to kill his duplicated selves so Madrox Prime could reabsorb the information. With Layla trapped in the future, alternative methods were needed but Jamie soon fell into a coma.
In the future, after being imprisoned in a mutant concentration camp, Layla and one of Madrox's duplicates met up with a young Lucas Bishop. After learning about the stories he was told about a mutant baby damning the mutant race, Layla stole a bomb from one of the security guards and threw it at the Madrox dupe, allowing Madrox Prime to wake up. Madrox awoke in a panic, relaying the information to the X-Men and with a M tattooed over his face eye. Layla is now stuck in the future, and it is unknown what happened to the other dupe.
During the event, Rictor also posed as a baseline human who hated mutants in order to infiltrate the Purifiers. Under the guise of "Joaquin Murrieta", Rictor pretended to shoot and perhaps fatally injure Wolfsbane in front of members of the group to gain entrance. He then gathered information from their computers to relay to the X-Men about their advanced technology and information regarding the whereabouts of the mutant baby.
The New X-Men, on a mission of revenge, interrupted his undercover duty blowing his cover. Luckily, Rictor was teleported away from the scene in time. Monet, Siryn, and Strong Guy's role in the mission was to participate in combat against the Marauders and the Acolytes on Muir Island. Wolfsbane participated in the X-Force as one of the vicious trackers, a role she would continue with undercover under the orders of Cyclops.
X-Factor was falling apart during the Divided We Stand story arc. Madrox has since nearly broken down particularly over the loss of Layla Miller. Siryn has revealed she is pregnant with Jamie's child, but has been unable to properly communicate with him since she found out.
Wolfsbane has decided to stay with X-Force, in part because she has seen a future in which she will kill Jamie Madrox. After a scornful goodbye, she parts ways with Jamie and only leaves a note for Rictor, with whom she's had a romantic relationship in the previous months.
Upon reading the letter, an already distraught Rictor decides to leave the team. As he leaves the building, he falls into a trap door that leaves him under the capture of X-Men villain Arcade and the Purifier he tricked into letting him into their group.
The group eventually comes to his rescue but not before Arcade escapes revealing that he has put a force-field around the city that will trap everyone inside as a bomb detonates the entire perimeter. The bomb, implanted within the ex-Purifier upon his last heart beat, prepares to detonate as he drinks his last sip of poison.
X-Factor became aware of the Secret Invasion of Earth. In the three part story arc with She-Hulk, X-Factor get their first client in their new location, Detroit, Michigan. The client is looking for his son, who happens to be former X-Man Darwin who happens to be traveling with Longshot.
Upon finding Darwin and Longshot and chasing them across Detroit, She-Hulk and Jazinda turn up resulting in a fight between X-Factor and She-Hulk. It is then revealed that Longshot isn't Longshot at all and is in fact Nogor, representative of the Skrull gods, whose presence on earth gives the Skrulls morale and helps them believe they are blessed in this war. Jazinda had told She-Hulk, which was the reason they were in Detroit and with everything out in the open, She Hulk and X-Factor make up and set about saving the world from the Skrulls.
Nogor is finally captured and is taken off into the distance and Darwin remains with the X-Factor team.
While Madrox, Monet, Strong Guy and Longshot are investigating the disappearance of Darwin, Val Cooper turns up with an escort of government agents to reveal to Siryn and Rictor that in fact X-Factor Investigations has been working for the government.
During this time Syrin goes into labor and Val Cooper is shot on the lawn. Siryn takes Val off to the hospital and herself to have her baby.
The gang return from their search and rescue mission for Darwin at the Karma project. Madrox and Siryn become engaged thanks to her asking the question. The baby is finally delivered and as a precaution Madrox follows the baby on its way to the nursery so he isn't stolen by the government.
Upon holding the new baby (now named Sean after his grandfather) it becomes apparent that this isn't any normal homosapien baby, surprise, surprise. A strange glow surrounds Sean and Madrox feels the same sensation as he does when he absorbs his dupes, then baby Sean, like a dupe is absorbed.
Siryn is obviously livid with Madrox and upon discovering the conception of her baby was with a dupe of Jamie and not Jamie himself, she promises to break his neck.
X-Factor Investigations recently disbanded. Havok joined Uncanny Avengers, Shatterstar and Rictor are now in Mojoworld, Pip apparently died, Wolfsbane and Darwin quit the team again, Siryn became Morrigan (a supernatural entity). Polaris was recruited for a mysterious project called X-Factor, Madrox & Layla are reunited as a couple, Longshot and Monet will return playing important roles.
X-Men: The Animated Series, The team appeared in the episode ''cold comfort'', it is where Iceman broke into their building (facility) to find his partner (girlfriend Polaris) and then ran afoul of the X-Men. When it came to start battle against the X-factor, Forge (one of the team mates) said it was to test them.
X-Factor was seen in two episodes of the Animated series. Mainly in Cold Comfort (Episode 41),
and also seen in Sanctuary Part 1 (Episode 51) when Magneto was addressing planet Earth.