Henry Walton (1746 - 1813). Henry Walton was an English painter and art dealer. Little is known of Walton's early life. In 1770, he began studying art at the St. Martin's Lane Academy, in London. Walton primarily worked as a portraitist, painting in oil and producing miniatures. Later he painted some genre works. Records show he later worked as a picture dealer and adviser to some major private collectors.