William Robertson Davies, CC, FRSC, FRSL (born August 28, 1913, at Thamesville, Ontario, and died December 2, 1995 at Orangeville, Ontario) was a Canadian novelist, playwright, critic, journalist, and professor. He was one of Canada's best-known and most popular authors, and one of its most distinguished "men of letters", a term Davies is sometimes said to have detested.

A series of three novels by Robertson Davies, consisting of Fifth Business (1970), The Manticore (1972), and World of Wonders (1975). Throughout the trilogy, Davies interweaves moral concerns and bits of arcane lore. The novels trace the lives of three men from the small town of Deptford, Ont., connected and transformed by a single childhood event: Percy "Boy" Staunton throws a snowball containing a stone at Dunstable (later Dunstan) Ramsay. Ramsay dodges the snowball and it hits Mary Dempster, who gives birth prematurely to a son, Paul, and slides into dementia. Fifth Business is an autobiographical letter written by Dunstan upon his retirement as headmaster of a boys' school; he has been tormented by guilt throughout his life. Boy Staunton lies at the bottom of Lake Ontario at the opening of The Manticore; the stone that hit Mrs. Dempster some 60 years earlier is found in his mouth. Much of the book describes the course of Jungian analysis undertaken by Boy's son David. World of Wonders tells the story of Paul Dempster. Kidnapped as a boy by a magician, he learns the trade and eventually becomes Magnus Eisengrim, one of the most successful acts on the European continent.