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 him Marquess of Hertford in 1640 and on 13 September 1660, shortly before his death on 24 October, the title of Duke of Somerset was granted to him as its legitimate heir; following its non-existence for 108 years. He outlived his three eldest sons and as the dukedom descends to heirs male of the holder of the 1547 grant it passed to William Seymour (1654–1671) who was the son of the third son mentioned (lived 1626–1654). The 3rd duke died unmarried and the title passed to John Seymour (bef. 1646–1675) the last surviving son of the 2nd Duke, his uncle.