Magneto (born Erik Lehnsherr) is a mutant with the ability to manipulate magnetic fields to his will and control metallic objects. He was a founding member of the X-Men, but left the group to form the Brotherhood of Mutants. Magneto firmly believed that mutants should fight back against their human oppressors by any means necessary, an ideal that conflicted with the goals of his longtime close friend Charles Xavier, who sought a more pacifist approach to mutant prosperity. As such, Magneto was often an adversary to the X-Men, but would team up with them when the situation called for it.