Richard Holloway's Leaving Alexandria: A Memoir of Faith and Doubt (Canongate) has won the PEN/Ackerley Prize 2013.
Holloway's book, which describes his struggle with faith, beat off competition from Will Cohu, Rachel Cusk and Colin Grant.
The PEN/Ackerley Prize is the only British literary prize dedicated to memoir and autobiography. It was founded in memory of editor and author J R Ackerley, and was first awarded in 1982. The winner receives a cheque for £2,500.
Peter Parker, chair of this year's judges, described the book as "a unanimous choice of the judges", and said: "J R Ackerley was never in the least drawn to Christianity, but I believe he would have admired Richard Holloway's Memoir of Faith and Doubt for its searching self-analysis, its admissions of fallibility, its questioning of authority, its wide range of literary references, its essential humanity and—perhaps above all—the very high quality of its prose."
Holloway was Bishop of Edinburgh before retiring from the position in 2000 at the age of 66.