"The Dark Phoenix Saga" is an extended X-Men comic-book storyline published by Marvel Comics. Created by writer Chris Claremont and artist John Byrne, the storyline first appeared in X-Men #129. It focuses on the superhero Jean Grey and the cosmic entity Phoenix Force. The storyline commonly refers to the story in Uncanny X-Men #129–138 of Jean Grey's corruption by the power of the Phoenix and the Hellfire Club, the destruction she causes, and ultimately her death. Sometimes included is Jean Grey's assumption of the Phoenix power and the repair of the M'Kraan Crystal in Uncanny X-Men #101–108.