Masters of Evil

The Masters of Evil is one of the largest and longest-running alliances of super-villains in history, led by assorted criminal masterminds and comprised of an ever-changing membership ranging from minor thugs to major menaces. In many ways, they are the criminal equivalent of the Avengers, the Masters' first and most frequent foes.

After seemingly slaying Captain America and Bucky during World War II, the Nazi scientific genius Heinrich Zemo had withdrawn to South America, where he subjugated a native tribe, carving out his own private kingdom. Zemo lived in seclusion until recent years when he learned that the Avengers had found and revived Captain America. Determined to destroy his old enemy but unwilling to face the Avengers alone, Zemo recruited the super-criminals Black Knight, Melter, and Radioactive Man (foes of Avengers members Giant-Man, Iron Man and Thor, respectively). Calling themselves the Masters of Evil, the villains drew the Avengers into battle by spraying the streets of New York with Zemo's Adhesive X, causing citywide chaos. Aided by adhesives expert Paste-Pot Pete, the Avengers defeated the Masters, and Zemo himself barely escaped.

Zemo formed a new alliance with Thor's foes Amora the Enchantress and Executioner. The trio mystically turned Thor against the Avengers, but the spell soon broke and Thor hurled them into another dimension. Upon returning, the Masters mutated embezzler Simon Williams into Wonder man, who infiltrated and betrayed the Avengers on Zemo's behalf; however, in the end, a conscience-stricken Williams sacrificed himself to save the Avengers. The Masters' brief alliance with the mysterious time lord  Immortus fared little better, resulting in another Avengers victory. Retrieving Black Knight and Melter from prison, the Masters regrouped in New York for an all-out assault on the Avengers while Zemo faced Captain America in the Amazon. The Masters were defeated yet again, and Zemo accidentally killed himself in battle.

With Zemo gone, the Masters broke up; but the mad robot Ultron (a rogue creation of Avengers founder Henry Pym), hiding his mechanical nature behind the costumed identity of the Crimson Cowl, recruited Melter, Radioactive Man, Klaw, and Whirlwind into a new Masters of Evil in a plot to destroy the Avengers. Ultron hypnotized Avengers butler Edwin Jarvis into compromising the Avengers' security system, even compelling Jarvis to act as his occasional stand-in, supposedly the "real" Crimson Cowl; but a new Black Knight (Dane Whitman), secretly the heroic nephew of his recently deceased predecessor, had joined Ultron's Masters to fight them from within. Thanks in part to the efforts of Whitman and a repentant Jarvis, the Masters were defeated; however, they soon regrouped (minus Ultron and Whitman) in an attempt to kidnap noted scientist Dr. T. W. Erwin from the annual Halloween parade in Rutland, Vermont. They were soundly defeated through the combined efforts of the Avengers and the short-lived feminist super-group known as the Lady Liberators.