The Mutant Resistance was formed by Magneto, who used his vast magnetic powers to steal several buildings from New York and used them to create Fortress X, a safe haven for mutants. Many mutants flocked to join him, and under his leadership they formed a mutant army, which fought to defend the Fortress from the human invaders who would see mutantkind extinct.[1]
Notes
From the thousandth day of Resistance to the revelation of the falseness of the Age of X, the only inhabitants of the Fortress X and members of the Mutant Resistance are the counterparts of Earth-616Utopia, the corporalized personalities of Legion (including the one who took Moira Kinross' identity) and the mental manifestation of Earth-811's Rachel Summers.