Born in Glasgow, he was educated at Glasgow University and served in the Royal Navy (1941-46). In 1954, while a schoolteacher, he won a short-story competition held by the Glasgow Herald, contributing a tale of adventure at sea. At the suggestion of William Collins, the publishers, he produced a full-length novel, HMS Ulysses, the next year, and this epic story of wartime bravery became an immediate bestseller. He followed it with The Guns of Navarone (1957), and turned to full-time writing. He preferred the term "adventure story" to "novel" in describing his work. His settings are worldwide, including the China Seas (South by Java Head, 1958), Greenland (Night Without End, 1960), Florida (Fear is the Key, 1961), the Scottish islands (When Eight Bells Toll, 1966), a polar scientific station (Ice Station Zebra, 1963) and the Camargue (Caravan to Vaccares, 1970). As well as two secret-service thrillers (written as "Ian Stuart"), The Dark Crusader (1961) and The Satan Bug (1962), he wrote a Western (Breakheart Pass, 1974) and biographies of T E Lawrence and Captain Cook. Other titles include Where Eagles Dare (1967), Force Ten From Navarone (1968) and Athabasca (1980). Most of his stories were made into highly successful films.