World War Hulk
The Illuminati was formed after the Kree-Skrull War, by Iron Man, Namor, Mr. Fantastic, Professor X, Black Bolt, and Doctor Strange. After the Kree-Skrull War, Iron Man realized that if the six had worked together, they could have each used their own respective information and stopped it. Along with Black Panther, he proposed a government of superhumans. However, many of them refused, for individual reasons.