In 1964, Norwich left the diplomatic service to become a writer. His books included histories of Sicily under the Normans (1967, 1970), Venice (1977, 1981), Byzantium (1988, 1992, 1995), the Mediterranean (2006), and the Papacy (2011). Norwich worked extensively in radio and television. He was host of the BBC radio panel game "My Word!" for four years (1978–82) and also a regional contestant on "Round Britain Quiz". 