He was born in 1885 in Cardiff, son of John Thomas Duncan of Llandaff. He was educated at Chard School, Somerset before arriving at Abingdon School, in January 1900, where he stayed until 1903. He excelled at sport and was part of the first XI cricket team during 1901, 1902 and 1903 and the football team. His brother Norman Duncan was Captain of the School in 1906 and a President of the OA Club.
