Riley rose to prominence as a fashionable society painter in London at a time when British portraiture was dominated by artists from the continent. He began practising at a young age, yet it was not until the death of Sir Peter Lely in 1680 that he was most successful, being appointed Painter in Ordinary to King Charles II the following year. Riley was famous for his unidealised portraits and was particularly skilled at rendering the sitters’ heads, leaving poses and drapery to be painted by his studio assistants. Riley’s career reached its climax in 1689 when, along with Sir Godfrey Kneller, he was jointly appointed Principle Painter to King William III and Queen Mary. There are however, no known portraits by Riley of these monarchs.