エドムンド・ボーフォート
It was later created in 1411 for Thomas Beaufort, who was later created Duke of Exeter. The peerages became extinct on his death. It was next created in 1441 for Edmund Beaufort who was later created first Marquess of Dorset (1442) then Duke of Somerset (1446). These titles were forfeited by the second duke in 1464.