Henry Thoby Prinsep was a friend of the painter George Frederic Watts, under whom his son first studied, and travelled with Watts in 1856–57 to Sir Charles Thomas Newton's excavation of Halicarnassus. He then went to Charles Gleyre's atelier in Paris. There James Abbott McNeill Whistler, Edward Poynter, and George du Maurier were among his fellow students, and he was later the original for Taffy in Du Maurier's novel "Trilby." After Paris, Prinsep passed to Italy. With Edward Burne-Jones he visited Siena and there made the acquaintance of Robert Browning, of whom he saw much in Rome during the winter of 1859–60.