A military historian, graphic artist, cookbook author and fiction writer, he is best known for his spy novel, The IPCRESS File (1962), which was later adapted into a film. His other published works include Declarations of War (1971), Twinkle, Twinkle, Little Spy (1976), and Basic French Cooking (1979).
He developed an interest in spy stories after witnessing the arrest of Nazi spy, Anna Wolcoff, when he was eleven years old. In his early adulthood, he worked for the Special Investigation Branch of the Royal Air Force.
He created the first British cover for Jack Kerouac's famous novel, On the Road.
He was born in London to a mechanic and chauffeur father and a cook mother. He graduated from the Royal College of Art in 1955.
His novel, The IPCRESS File, was made into a film starring Michael Caine.