He was born in Shirley, Derbyshire, where his father was vicar. His mother was descended from the poet William Cowper, hence his middle name. His two younger brothers, Llewelyn Powys and Theodore Francis Powys, also became well-known writers. Other brothers and sisters also became prominent in the arts. John studied at Sherborne School and Corpus Christi College, Cambridge, and became a teacher and lecturer; as lecturer, he worked first in England, then in continental Europe and finally in the USA, where he lived in the years 1904-1934. He made his name as a poet and essayist, moving on to produce a series of novels, mostly historical romances, and some works of philosophy. Having returned to Britain, he lived first in England and then in Wales, where he stayed until his death.