Duke of Somerset years after losing his position as Lord Protector, his titles were forfeited and he was beheaded on 22 January 1552. He was replaced in the minority government of Edward VI by John Dudley, Duke of Northumberland, whose pragmatic style contrasted with Seymour's mixture of idealism and arrogance. In 1644 Charles I granted the earldom of Glamorgan to Edward Somerset (1613–1667). He was a descendant of Charles Somerset, the illegitimate son of Henry Beaufort, 3rd Duke of Somerset. In return for obtaining military help from Ireland he promised Edward the title of Duke of Somerset. Under the Commonwealth Edward was banished
Duke of Somerset On his death without issue on 29 April 1675 only the Marquessate of Hertford became extinct. His distant cousin Francis Seymour, 3rd Baron Seymour of Trowbridge (1658–1678) became 5th Duke of Somerset. Francis was the eldest surviving son of Charles Seymour (1621–1665), whose father Sir Francis Seymour (c. 1590–1664), a younger brother of the 2nd Duke of Somerset, had been created Baron Seymour of Trowbridge in 1641. When the 5th Duke died unmarried in 1678, the title passed to his brother, Charles Seymour (1662–1748), youngest son of the 2nd Baron Trowbridge. The 6th Duke, was known as "the Proud Duke",