Duke of Somerset

Duke of Somerset is a title in the peerage of England that has been created several times. Derived from Somerset, it is particularly associated with two families; the Beauforts who held the title from the creation of 1448 and the Seymours, from the creation of 1547 and in whose name the title is still held.

The only subsidiary title of the Duke of Somerset is Baron Seymour, which is used as a courtesy title for the eldest son and heir of the Duke. The Duke of Somerset's heir's courtesy title is the lowest in rank of all heirs to Dukedoms in the peerages of the British Isles, yet a Lord Seymour's precedence is higher than his title suggests, by virtue of the seniority of the Dukedom of Somerset (The only more senior non-royal Duke is the Duke of Norfolk).

Several other titles have been held by the Duke of Somerset, but have become extinct. These include: Earl of Kendal (created 1443; extinct 1444), Viscount Rochester (created 1611; extinct 1645), Viscount Beauchamp of Hache (created 1536; forfeit 1552), Earl of Hertford (created 1537; forfeit 1552 and created 1559; extinct 1750), Marquess of Hertford (created 1640; extinct 1675), Baron Seymour of Trowbridge (created 1641; extinct 1750), Baron Percy (created 1722; separated 1750), Baron Cockermouth (created 1749; separated 1750), Earl of Egremont (created 1749; separated 1750), and Earl St. Maur (created 1863; extinct 1885).

The ducal seat is Bradley House (Wiltshire) in Maiden Bradley with Yarnfield, Wiltshire, with a secondary estate at Berry Pomeroy Castle, Totnes, Devon.