Duke of Beaufort (), a title in the Peerage of England, was created by Charles II in 1682 for Henry Somerset, 3rd Marquess of Worcester, a descendant of Charles Somerset, 1st Earl of Worcester, legitimised son of Henry Beaufort, 3rd Duke of Somerset, a Lancastrian leader in the Wars of the Roses. The name Beaufort refers to a castle in Champagne, France (now Montmorency-Beaufort). It is the only current dukedom to take its name from a place outside the British Isles. The Dukes of Beaufort descend in the male line from the House of Plantagenet through John of Gaunt, son of Edward III. This statement was challenged after the analysis of the Y chromosomal DNA of the remains of Richard III. Most living male heirs of the 5th Duke of Beaufort were found to carry a relatively common Y chromosome type, which is different from the rare lineage found in Richard III's remains. The instance of false paternity could have occurred anywhere in the numerous generations separating Richard III from the 5th Duke of Beaufort. The break also could have occurred with Richard III's grandfather Richard of Conisburgh, whose paternity has been called into question although he was acknowledged by his father. The Beaufort Castle was in possession of John of Gaunt, and the surname Beaufort was given to Gaunt's four legitimised children by his mistress and third wife, Katherine Swynford. This was the foundation of the House of Beaufort, Dukes of Somerset. A descendant of the Beauforts through his mother was Henry VII of England. Charles Somerset, 1st Earl of Worcester,KG (c. 1460 – 15 March 1526), was the bastard son of Henry Beaufort, 3rd Duke of Somerset by his mistress Joan Hill. The Duke of Beaufort holds two subsidiary titles: Marquess of Worcester (created 1642) and Earl of Worcester (1514). The title Marquess of Worcester is used as a courtesy title by the duke's eldest son and heir. The title Earl of Glamorgan is used by the eldest son of the heir apparent to the dukedom. The Earl of Glamorgan's eldest son is known as Viscount Grosmont. The Earldom of Glamorgan and Viscountcy of Grosmont derive from an irregular creation by Charles I in 1644 in favour of Edward Somerset, who later succeeded his father as 2nd Marquess of Worcester. Although the Earldom of Glamorgan and Viscountcy of Grosmont were not recognised as substantive titles at the restoration