I am a painter, and in addition to living off the sale of my paintings, since 1966 (when I left art school) I have supported myself as an art historian and lecturer on art. A number of my paintings and prints are in various public and private collections. Being something of an authority on Britain's greatest painter, J.M.W.Turner, I am the author of eleven bestselling books and catalogues on the artist; a Vice-President of the Turner Society and formerly its Chairman for many years; and the Founding Editor of Turner Studies, a scholarly journal published by the Tate Gallery between 1980 and 1991. I have frequently contributed articles on Turner to specialist and popular journals and newspapers. In 1996-7 I was appointed a Nuclear Magnox Turner Scholar at the Clore Gallery for the Turner Collection, which period of research resulted in the exhibition 'Turner's Watercolour Explorations' held at the Tate Gallery in 1997. I was invited to curate the major exhibition 'Turner: The Great Watercolours' held at the Royal Academy of Arts, London, in 2000-2001 to mark the 150th anniversary of Turner's death. I also curated the 'Golden Age of Watercolours' exhibition held at the Dulwich Picture Gallery, London; the Djanogly Art Gallery, Nottingham; and at the Yale Center for British Art, New Haven, Connecticut. Since 2007 I have been working upon ‘J.M.W. Turner: A Life in Art’, a one-million word biography to be published by Yale University Press on behalf of the Paul Mellon Centre for Studies in British Art, the first volume of which is planned to appear in 2014.

Because I am a contemporary painter who taught the history of modern and contemporary art for many years after 1966, I have naturally always been interested in modern artists. Accordingly I have written a book on the great Romanian sculptor, Constantin Brancusi, who is a particular interest of mine. Further artists on whom I have written books include Salvador Dalí, Andy Warhol and David Hockney. I have lectured all over the world, and am much in demand as a lecturer, due to my skills in communicating both my knowledge and enthusiasm for my subjects.