He was baptized on 27 January 1717 at Easton in Wiltshire.[1] He succeeded his father as Duke of Somerset on 12 December 1757. He was named a Privy Councillor by George II and in 1783 was awarded an annual pension, which along with his financial management and reclusiveness contributed to the growth of his fortune.[2]
He died on his 75th birthday, unmarried and childless, and was interred on 11 January 1792 at Maiden Bradley, near Warminster, Wiltshire. His titles passed to his brother Webb Seymour.