John Julius Norwich was born in 1929. He was educated at Upper Canada College, Toronto, at Eton, at the University of Strasbourg and, after a spell of National Service in the Navy, at New College, Oxford, where he took a degree in French and Russian

. In 1952 he joined the Foreign Service, where he remained for twelve years, serving at the embassies in Belgrade and Beirut and with the British Delegation to the Disarmament Conference at Geneva. In 1964 he resigned from the service in order to write.

His many and varied publications include two books on the medieval Norman Kingdom in Sicily, The Normans in the South and The Kingdom in the Sun, which are published by Penguin in one volume entitled The Normans in Sicily; two travel books, Mount Athos (with Reresby Sitwell) and Sahara; The Architecture of Southern England; Glyndebourne; two anthologies of poetry and prose, Christmas Crackers and More Christmas Crackers; and A History of Venice, originally published in two volumes. He is also the author of a three-volume history of the Byzantine Empire: Byzantium: The Early Centuries, Byzantium: The Apogee and Byzantium: The Decline and Fall. Many of his books are published by Penguin. In addition he has written and presented some thirty historical documentaries for television, and is a regular lecturer on Venice and numerous other subjects.

Lord Norwich was chairman of the Venice in Peril Fund, Co-chairman of the World Monuments Fund and a former member of the Executive Committee of the National Trust. He was a Fellow of the Royal Society of Literature, the Royal Geographical Society and the Society of Antiquaries, and a Commendatore of the Ordine al Merito della Repubblica Italiana. He was made a CVO in 1993. He passed away in June 2018.