The Illuminati is a group of superheroes who joined forces and secretly work behind the scenes in the Marvel Universe. The group was formed after the Kree-Skrull War. That war was depicted in Avengers #89-97 (1971-1972), however the Illuminati were not established to exist until their first appearance in New Avengers #7 (July 2005) , written by Brian Michael Bendis. Their history was discussed in the special New Avengers: Illuminati (May 2006) .

The members are Professor X, Doctor Strange, Mister Fantastic, Namor, Iron Man, and Black Bolt.

Maria Hill, Director of SHIELD, approaches Iron Man concerning the Hulk, who has recently destroyed Las Vegas. Iron Man presents a solution to the problem of the Hulk to the Illuminati (excluding an absent Professor Xavier), suggesting that they shoot him into space. Namor, alone, dissents to the plan. He believes that they have no right to banish their ally from Earth and accuses them of not helping to cure Bruce Banner to the best of their abilities. The other four members vote in favour of the plan, and Namor departs. While leaving, he says that the Black Panther was correct, and predicts that the Hulk will return to seek justified revenge.

During Civil War, Reed is contacted by Mastermind Excello, who informs him that Hulk did not land on the intended planet. When the Hulk ultimately returns to Earth, he seeks revenge on the Illuminati. His first act is to attack and defeat Skrull Bolt at the Inhuman settlement on the moon. After providing New York with a twenty-four-hour time limit to hand the other three Illuminati over to him, the Hulk approaches Xavier at his mansion to determine whether he would have supported the Illuminati plan had he been present. He battles the X-Men, but after learning of the mutant population's recent severe losses as a result of M-Day, the Hulk decides that the X-Men have suffered enough and departs ^[18]. Having then taken over Manhattan Island, the Hulk is attacked by Iron Man in a new 'Hulkbuster' armour, only for him to be defeated and Stark Tower to be destroyed. Despite the aid of the other members of the Fantastic Four- including temporary members the Black Panther and Storm, the same fate befalls Mr. Fantastic. Dr. Strange tries to enter the Hulk’s mind, but Hulk tricks Strange into presenting himself in a physical form that he attacks upon appearance. Strange later invokes and is possessed by the demon spirit of Zom, hoping that he could stop the Hulk before it was too late. However he loses control of his new found power, and he almost caused some civilians to die during his battle with the Hulk. Although the Hulk saves them, this action makes Strange lose his confidence in his powers and makes him weak enough for the Hulk to defeat.