Michael was born in London in 1939. At the age of fifteen he became the editor of the Tarzan Adventures Magazine. After he was thrown off the magazine for trying to publish too much text on a comic strip magazine he began selling stories to science fiction and fantasy magazines. It is then that he came up with the concept of the eternal champion, which appeared in many of his novels and of whom the most famous character is Elric. Michael paved the way for modern contemporary fiction by taking the New Worlds Science Fiction magazine and turned it into a 60's alternative culture. In the 80's Michael begin concentrating more on literary work and less on fantasy novels. At a later stage he returned to writing fantasy and produced two more Elric volumes among other writings.
Michael is currently married to Linda Steele whom he married in 1983. He was previously married twice. His first wife is Hilary Bailey with whom he has three children. They were married from 1962 to 1978. His second wife was Jill Riches.