[2] Born in Lausanne, Switzerland, and raised in London under the name Gai, Eaton was the son of the married Francis Errington and his mistress, Ruth Frances Muddock; to hide her son's illegitimacy, Ruth claimed that she had been married to a Canadian, Charles Eaton (an invention of Errington's, by then supposedly deceased), and that Charles had fathered the child.

[1] Brought up agnostic,[3] Eaton was educated at Charterhouse School and King's College, Cambridge, where he studied history and entered into a correspondence with the novelist Leo Myers.

[1] Eaton was a consultant to the Islamic Cultural Centre at Regent's Park Mosque in London for 22 years.

Regarding the 2003 invasion of Iraq, in an interview with Emel magazine, he stated, "I am very torn either way and I cannot quite make up my mind what I think ... [Saddam] was our monster, it should have been for us to deal with him.

Eaton's last book and autobiography, A Bad Beginning and the Path to Islam (2009), was published by Archetype in January 2010.