In the movies, Magneto was born Erik Lensherr some time in the late 1920s to a German Jewish family. His first known manifestation of his powers occurs during his interment at a concentration camp in Poland, where he bends the gates of the camp when he is locked on one side and his parents on the other. Because of his abilities, he is studied and experimented upon by camp "doctors". One such experiment involves the doctor shooting Erik's mother when he fails to manipulate a five-reichsmark coin. As well as the expected psychological scarring, the conclusion drawn from that experiment is that Erik's powers manifest when he's angry.
In the 1960s, Erik Lensherr is on a vigilante quest to kill the man who destroyed his life. He meets Charles Xavier off the coast of Florida, when the telepath stops him from towing himself behind the former doctor's submarine, an action which would have drowned him. Both Lensherr and Xavier are tracking the same man, alias "Sebastian Shaw", who is an identified Communist and target of the American CIA. He works with Xavier for a time, recruiting young mutants for a team to track down and apprehend Shaw. One of these mutants is Raven, a young shapeshifter living as Charles Xavier's sister and disguising herself as a blonde teenager, who takes the alias "Mystique" and names Lensherr "Magneto".
During the Cuban Missile Crisis, Magneto is the only mutant to confront Sebastian Shaw directly. Rather than apprehend the man, he kills him.
In the movies, Magneto is involved in the accident that causes Professor Xavier's paraplegia. During the Cuban Missile Crisis, he deflects a bullet shot at him, and it hits Xavier, severing the man's spine.
In the early 2000s, Magneto plans a bio-terroristic strike against the world's leaders. With the help of his "Brotherhood", he builds a machine which, when activated, creates an energy wave that alters the genetic code of humans and makes them mutants. Magneto either does not know or just does not care that this effect is unstable, and that the victims of such a wave die after only a few days. Magneto sends Mystique to kidnap Rogue from Xavier's school, and he uses her to power the machine. Magneto is stopped before the wave is powerful enough to reach the intended target, and is captured.
Magneto later breaks out of the prison cell built specially to house him, and works with the X-Men to stop William Stryker, a military man who kidnapped Xavier's students using his mutant son's cerebrospinal fluid as a truth serum to learn everything Magneto knows about the school. Magneto gets his revenge on Stryker by lashing him to a boulder before a dam breaks, leaving him there to drown. Magneto, Mystique, and willing recruit Pyro (John Allerdyce) escape the flood by leaving the lake bed in a helicopter.
Magneto is vehemently against the "mutant cure", and amasses a mob of like-minded mutants to storm Alcatraz. When rescuing Mystique, as well as recruiting both Multiple Man and Juggernaut, he is fired upon by humans armed with "cure darts". Mystique saves him by letting the darts strike her, but becomes "human" and is left behind when Magneto makes his getaway. Magneto is later stabbed with a "cure dart" by Beast, which nullifies his powers.
At the end of the current movies' storyline, Magneto is seen at a chess table a park, trying to move a metal chess piece with his powers. He doesn't manipulate it easily, but he succeeds, which implies that the "cure" may only be temporary.
Alternately, Magneto was born Max Eisenhardt sometime in the late 1920s to a middle class German Jewish family whose father, Jakob Eisenhardt was a highly decorated World War I veteran. Surviving discrimination and hardship during the Nazi rise to power, Kristallnacht, and the passing of the Nuremberg Laws, in 1939 Max and his family fled to Poland where they were captured during the German invasion of Poland and sent to the Warsaw Ghetto. Max and his family escape the Ghetto, only to be betrayed and captured again. His mother, father, and sister were executed and buried in a mass grave, but Max survived possibly due to the manifestation of his powers. Escaping from the mass grave, he is ultimately captured yet again and sent to Auschwitz, where he eventually becomes a Sonderkommando. While at Auschwitz, Eisenhardt reunites with a Roma girl named Magda, with whom he had fallen in love when he was younger, and with whom he escapes the prison camp during the October 7th 1944 revolt. Following the war, he and Magda move to the Ukrainian city of Vinnytsia, and adopts the name "Magnus". Magda and Magnus have a daughter named Anya, and live uneventfully until one night when an angry mob burned their home down with Anya still inside. Enraged at the mob preventing him from rescuing Anya, the young Magneto's powers manifest uncontrollably, killing the mob and destroying a part of the city. Magda, terrified at Magneto's power, leaves him and later dies giving birth to the mutant twins Quicksilver and the Scarlet Witch. Wanted by the authorities for the deaths and destruction in Vinnytsia, while searching for Magda, Magnus paid a Romanian forger George Odekirk, to create the cover identity of "Erik Lehnsherr the Sinte gypsy" for him.
"Erik", relocated to Israel, where he met and befriended Charles Xavier while working at a psychiatric hospital near Haifa. There, lengthy debates are held by the two regarding the consequences humanity faces with the rise of mutants, though neither reveals to the other that they both in fact possessed mutant powers. However, they are forced to reveal their inherent abilities to one another, while facing Baron Von Strucker and HYDRA. Following the battle, Erik (now dressed as Magneto) leaves, realizing that his and Xavier's views are incompatible, with a cache of hidden Nazi gold, which provided him with the financing to launch his goals.