The Brotherhood of Mutants is a group dedicated to the cause of mutant superiority over humans. Throughout its various incarnations, the Brotherhood's agenda has gravitated towards either subjugating the human race to the will of mutants or eradicating humanity altogether. Magneto formed the Brotherhood of Evil Mutants, including Astra, Toad, Quicksilver, Scarlet Witch, and Mastermind, shortly after the public debut of the X-Men. After a falling out with Astra that led to her quitting the team, Magneto had the Brotherhood initiate an attack upon humans that was thwarted by the X-Men. Magneto then attempted to recruit the thunder god Thor into his Brotherhood, but Thor refused. The Blob was the next candidate for recruitment, but ultimately declined to join after seeing the way Magneto mistreated his followers. Mastermind then sought to recruit Unus the Untouchable; however, he was blackmailed by the X-Men into declining the offer in exchange for reversing his then-amplified powers. During an encounter with the enigmatic Stranger, Magneto and the Toad were captured and taken to the Stranger's homeworld, shortly after which Quicksilver and the Scarlet Witch joined a revamped version of the Avengers led by Captain America.