Duncan was born in 1958 in Reading, 40 miles west of London. He has been painting professionally since 1985.

Primarily a landscape painter, he has travelled widely in Europe to find subjects for his landcscapes. Influenced by the impressionist school, he takes a particular interest in colour and texture. He usually works on a series of paintings on a theme, developing the colour and composition.

Duncan has exhibited in England and France, and is published by Woodmansterne.