Max Eisenhardt (aka, Magneto) is a character in the fictional Marvel universe, who was created in 1963. At times he has been a supervillain and at other times an anti-hero. Magneto is one of Marvel's A-list characters, and one of its most popular characters.
Magneto is a man who has been shaped by tragedy and trauma, a survivor of the Holocaust who has seen the worst mankind is capable of and refuses to let that happen to mankind. He is a man who is willing to do whatever is necessary to protect his "people" (mutantkind), and willing to use any means. While he has at times been willing to work with humans and live with them, at other times he has advocated separatism or outright conquest of mankind by mutants. Among the would-be conquerors of Earth he is among the most enlightened, sophisticated, and benevolent of tyrants similar to Doctor Doom and Fu Manchu (and just as ruthless), and is not a genocidal hate filled man like the Red Skull. Magneto is an Omega-level mutant, one of the most powerful beings on Earth.
He has fought the X-Men, the Avengers, and various other superheroes. Magneto has battled various governments (including both the United States and the Soviet Union), fascist organizations (e.g. Hydra), anti-mutant human supremacist groups, supernatural foes, and extra-terrestrials. He was the founder and leader of the Brotherhood of Evil Mutants, the leader of the Acolytes, and has been a member of the Hellfire Club's Inner Circle (a secret society of rich and powerful mutants). Magneto has been a teacher at the Xavier Institute, an ally of the X-Men, and at times a member of the X-Men.
Magneto has been the master of various asteroid strongholds and space stations, owned various subterranean and volcanic bases, and ruled over the Savage Land and later the island of Genosha. In the Berumda Triangle he raised the eldritch Island M to the surface, not knowing of Quoggoth it's imprisoned Old One. Later when he and the X-Men returned to the island and established themselves, they were forced to battle its eldritch defenses which had been activated by an alien. Recently he has moved to the island of Krakoa like most of mankind, where he is one of its defacto ruling triumvirate.