A.J. (Archibald Joseph) Cronin was born in Cardross, Scotland on February 19, 1896 and died a millionaire in Montreaux, Switzerland on January 6, 1981. He was educated at Glasgow University Medical School and served as a surgeon in the Royal Navy during World War I. After the war, he investigated occupational diseases in the coal industry and worked as a general practitioner in Wales and London. His first novel, Hatter's Castle, written in 1931, was an immediate success, and Cronin gave up the practice of medicine to become a full-time author. He was an extremely popular writer in his time; in fact, in 1937, The Citadel broke all publishing records. His publisher, Gollancz, printed 10,000 hardback copies of the book every week for many months. Cronin typically drew on his medical background in writing his books, and his most popular character was Doctor Finlay, the main character in his Scottish novels. These later provided the background for the television series, "Doctor Finlay's Casebook," which was hugely successful. Many of his other books were made into films, including The Stars Look Down, The Citadel, and The Keys of the Kingdom.