A Scottish author of thriller and adventure novels, he is best known for works such as Where Eagles Dare (1967) and The Guns of Navarone (1957). Several of his works, including Ice Station Zebra (1963), were made into successful films.
He served in the Royal Navy during World War II. He subsequently graduated from the University of Glasgow with a degree in English.
He wrote a handful of his works under the pseudonym of Ian Stuart.
With his first wife, Gisela Heinrichsen, he had two biological sons and one adopted son. He wed his second wife, Mary Marcelle Georgius, in 1972.
He has been compared to contemporary writer and James Bond series creator, Ian Fleming.