Born in Chicago, Illinois, Marc Spector is a Jewish-American rabbi's wayward son. As an adult, Spector had been a heavyweight boxer before becoming a U.S. Marine, afterwards he left the United States military to become a mercenary. He later becomes a strong and skilled combatant and befriends the French pilot Jean-Paul DuChamp, whom he affectionately calls "Frenchie". While working for the African mercenary Raoul Bushman in Egypt, the group stumbles upon an archaeological dig whose crew includes Dr. Peter Alraune and his daughter Marlene. The dig had uncovered an ancient temple where artifacts included a statue of the Egyptian moon god Khonshu. Intent on looting the dig, Bushman kills Dr. Alraune. In response to Alraune's murder, Spector challenges Bushman to personal combat and is defeated by Bushman and left to die in the sub-zero temperatures of the desert night.


The Egyptians who worship the ancient gods find Spector and carry him to their temple. Helpless before the statue of Khonshu, Spector's heart stops. Khonshu appears to him in a vision, offering Spector a second chance at life if he becomes the god's avatar on Earth. Spector awakens, wraps himself with the silver shroud that covers Khonshu's statue, and again confronts Bushman. He defeats Bushman and returns to America with Marlene Alraune, Frenchie, and the statue of Khonshu. Deciding to become a crimefighter, Spector creates a silver cloaked costume, based on the silver shroud, and becomes Moon Knight aka "The Fist of Khonshu".