The Club's highest ranking members belong to its Inner Circle, who dress in late Eighteenth Century costumes for Circle meetings and other formal occasions involving the Club. The Hellfire Club in New York was founded in 1778 by former Member of Parliament Sir Patrick Clemens, and his mistress, the renowned actress Diana Knight who served as its first leaders under their Club titles of Black King and Black Queen. The members hold positions named after chess pieces: the leaders are King end Queens, followed by Bishops, Knights, Rooks, and Pawns. It is possible for there to be two Kings (a Black King and a White King) or two Queens (Black and White) in office simultaneously. If a member of one faction of the Inner Circle displaces a member of another faction as King or Queen, he or she usually names his rank after the opposite color to his predecessor's; Hence, when Sebastian Shaw deposed the most recent former leader, a White King, he became a Black King.
Unknown to most of the Club members, the Inner Circle members are engaged in a conspiracy to dominate the world through the accumulation of economic power and political influence. The Inner Circle commands great financial resources, highly advanced technology, and a large body of mercenaries (many of whom wear red and blue uniforms with masks), all of which they use in their subversive activities.
The Hellfire Club has a minor skirmish with the X-Men and Donald Peirce's arm is cut off. He discovers he is a cyborg and loses his bid for Kingship. He disappears.
Mastermind searches for membership and tricks Phoenix into becoming a member of the Inner Circle. When Phoenix comes back to reality she kills Mastermind and awakens as the Dark Phoenix, destroying the Inner Circle's base.