John Cantacuzene reigned as Byzantine emperor in Constantinople from 1347 to 1354. A man of varied talents, as a scholar, soldier, statesman, theologian and monk, he was unique in being the only emperor to narrate the events of his own career. His memoirs form one of the most interesting and literate of all Byzantine histories. Following his abdication in 1354, he lived the last thirty years of his life as a monk, a writer and a grey eminence behind the throne.

This book is not a social or political history of the Byzantine Empire in the fourteenth century. It is a biography of a much maligned man who had a hope, however naive, of coming to terms with the emerging Muslim world of Asia and of winning the co-operation of western Christendom without compromising the Orthodox faith of the Byzantine tradition.