Born in London in 1848 to the artist Edward Duncan and Berthia née Huggins, the daughter of British marine painter William John Huggins. He studied art at the British Museum and the Heatherley School of Fine Art and served a seven-year apprenticeship at the Royal Academy of Arts. In 1874, he was elected an Associate of the Royal Watercolour Society. Proud of this distinction, he sometimes appended "A.R.W.S." to his name when he signed his works.