Created by Doug Moench and Don Perlin, Moon Knight first appeared in Werewolf by Night #32, 1975.

The character was actually casted as a villian during his debut, but received positive responses from readers and was later recasted as a superhero instead. However, Moon Knight did not receive his own solo comic till 1980, when artist Bill Sienkiewicz joined the creative team.

Born in Chicago, Illinois, Marc Spector is an American rabbi's wayward son. As an adult, Spector has been a heavyweight boxer, a U.S. Marine, and a mercenary. He becomes a strong and skilled combatant and befriends the French pilot Jean-Paul DuChamp, whom he 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.

Roaming Egyptians who worship the ancient Egyptian gods find Spector and carry him to their temple. There, Spector's heart stops, with Khonshu appearring 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.

Deciding to become a crimefighter, Spector creates a silver cloaked costume, based on the silver shroud, and becomes the Moon Knight.

Unlike some other superheroes, there was no one else who had donned the costume besides Marc Spector. But his career as the mysterious vigilante are somewhat eventful. Through the years, we have seen the hero joined the Defenders briefly, fighting criminals alongside the likes of Hulk and Dr Strange. And at a later time, he even joined the West Coast Avengers, Secret Avengers, and eventually the main team of Avengers for a short while. At his earlier time as the Moon Knight, he even adopted the son of his enemy (Jeff Wilde) as his sidekick at one time, named Midnight. He was killed in a fight with their arch-enemy the Secret Empire, brought back to life as per many other superhero characters at a later time, and last known to be seemingly finished off for good by his mentor the Moon Knight.

In the latest revamp, Marc Spector was depicted to have awaken in a mental institution, with no recollection of his past or what so ever...