Costain was born in
Brantford,
Ontario to John Herbert Costain and Mary Schultz. He attended high school there at the
Brantford Collegiate Institute. Before graduating from high school, he had written four novels, one of which was a 70,000 word romance about
Maurice of Nassau, Prince of Orange. These early novels were rejected by publishers. His first writing success came in 1902 when the
Brantford Courier accepted a mystery story from him, and he became a reporter there (for five dollars a week). He was an editor at the Guelph
Daily Mercury between 1908 and 1910. He married Ida Randolph Spragge (1888–1975) in
York Township, Ontario on January 12, 1910. The couple had two children, Molly (Mrs.
Howard Haycraft) and Dora (Mrs. Henry Darlington Steinmetz). In 1910, Costain joined the Maclean Publishing Group where he edited three trade journals. Beginning in 1914, he was a staff writer for and, from 1917, editor of the
Toronto-based ''
Maclean's magazine. His success there brought him to the attention of The Saturday Evening Post'' in
New York City where he was fiction editor for fourteen years. In 1920, he became a naturalized U.S. citizen. He also worked for
Doubleday Books as an editor 1939–1946. He was the head of
20th Century Fox's bureau of literary development (story department) from 1934 to 1942. In 1940, he wrote four short novels but was "enough of an editor not to send them out". He next planned to write six books in a series he called "The Stepchildren of History". He would write about six interesting but unknown historical figures. For his first, he wrote about the seventeenth-century pirate John Ward aka
Jack Ward. In 1942, he realized his longtime dream when this first novel
For My Great Folly was published, and it became a bestseller with over 132,000 copies sold. The
New York Times reviewer stated at the end of the review "there will be no romantic-adventure lover left unsatisfied." In January 1946, he "retired" to spend the rest of his life writing, at a rate of about 3,000 words a day. Raised as a
Baptist, he was reported in the 1953
Current Biography to be an attendant of the Protestant
Episcopal Church. He was described as a handsome, tall, broad-shouldered man with a pink and white complexion, clear blue eyes, and a slight Canadian accent. He was white-haired by the time he began to write novels. He loved animals and could not even kill a bug (but he also loved
bridge, and he did not extend the same policy to his partners). He also loved movies and the theatre (he met his future wife when she was performing Ruth in
The Pirates of Penzance). Costain's work is a mixture of commercial history (such as
The White and The Gold, a history of
New France to around 1720) and fiction that relies heavily on historic events (one review stated it was hard to tell where history leaves off and
apocrypha begins). His most popular novel was
The Black Rose (1945), centered in the time and actions of
Bayan of the Baarin also known as Bayan of the Hundred Eyes. Costain noted in his foreword that he initially intended the book to be about Bayan and
Edward I, but became caught up in the legend of
Thomas Becket's parents: an English knight married to an Eastern girl. The book was a selection of the
Literary Guild with a first printing of 650,000 copies and sold over two million copies in its first year. In 1950, it was made into
a successful film starring
Orson Welles as Bayan and
Tyrone Power as Walter. His research led him to believe that
Richard III was a great monarch tarred by conspiracies, after his death, with the murder of the
princes in the tower. Costain supported his theories with documentation, suggesting that the real murderer was
Henry VII. He also wrote four short stories for ''Ellery Queen's Mystery Magazine'' in the 1940s under the pseudonym Pat Hand. Three of the stories ("The Showdown," "The Imponderables," and "The Ace of Spades") feature gambler Careful Jones, who enjoys winning against rich men and has a Robin Hood streak. Costain died in 1965 at his New York City home of a
heart attack at the age of 80. He is buried in the Farringdon Independent Church Cemetery in Brantford. ==Awards and honours==