A prolific exhibitor, his solo shows include Hay Galleries, Hay-on-Wye, 1974, Tom Caldwell Gallery, Belfast & Dublin 1976, and Trumpington Gallery, Cambridge 1980.

He has also been involved in many group exhibitions, including the Royal Portrait Society in 1975, the Royal Society of British Artists from 1975 to 1987, and the Royal Academy Summer Exhibition from 1972 to 1987.

He was a prize winner in the 1972 Discerning Eye exhibition at the Mall Galleries, London, has written many books and articles, and has been a regular contributor to magazines such as The Artist since the mid-1970's.

Horton has taught in art schools and summer schools in Britain & abroad. His works are in the collections of Girton, Newnham and Trinity Colleges, Cambridge. He now lives in Cambridge.