Charles Seymour, 6th Duke of Somerset the pride of birth and rank amounted almost to a disease". Charles was the second son of Charles Seymour, 2nd Baron Seymour of Trowbridge (died 1665), of Marlborough Castle in Wiltshire, by his wife Elizabeth Alington (1635–1692). The 2nd baron was (in a junior line) a great-great-grandson of Edward Seymour, 1st Duke of Somerset (executed 1552), brother of Queen Jane Seymour, uncle of King Edward VI and Lord Protector of England. Charles was educated at Harrow School and Trinity College, Cambridge, where his portrait by Nathaniel Dance-Holland survives in the College's collection. In 1675, Charles's elder brother Francis Seymour, 5th
Duke of Somerset Duke's death he was succeeded by his eldest son Edward Seymour (1717–1792). He died unmarried and was succeeded by his brother Webb Seymour (1718–1793) who became the 10th Duke. His son Edward Adolphus Seymour (1775–1855) was a noted mathematician and became the 11th Duke upon his father's death. He changed the family name to St. Maur but Seymour was still very often used. The 11th Duke was succeeded by his eldest son Edward Adolphus Seymour (1804–1885) who was created Earl St. Maur, of Berry Pomeroy in 1863. His eldest son who predeceased him Edward A. F. Seymour (1835–1869) was known