James Byres of Tonley was an architect and antiquary who did much to shape neo-classical taste in Britain. Born on the Tonley estate in Aberdeenshire, Byres spent most of his adult life in Rome where he became the principal antiquarian guide to young aristocrats on their ‘grand tour’. He collected and dealt in antique sculpture and works of art, but he also had an interest in geology and fossils. In 1790 Byres left Rome and spent the next twenty-seven years as laird of Tonley, making numerous improvements to the estate. This portrait medallion was made by James Tassie, who was a lifelong friend of Byres. Tassie developed a secret recipe to make the white glass paste and used this technique to capture some 500 likenesses.