Katherine Swynford, Duchess of Lancaster (born Katherine de Roet, – 10 May 1403), also spelled Katharine or Catherine, was the third wife of John of Gaunt, Duke of Lancaster, the fourth (but third surviving) son of King Edward III.
Daughter of a knight from Hainaut, Katherine was brought up at the English royal court, later found herself in the service of Blanche of Lancaster, the first wife of John of Gaunt. At that time, she was married to Hugh Swynford (or de Swynford), one of the Duke's knights. After the death of the Duchess, Katherine became the lady-in-waiting of her daughters, and also took care of them.
After the death of Hugh Swynford (or de Swynford), she became a member of the household of the Duke's new wife, Constance of Castile, and she was given management of the estates of her deceased husband in Lincolnshire: Coleby and Kettlethorpe. She soon became the mistress of John of Gaunt. From this connection, at least four children were born, who received the surname Beaufort after one of their father's French estates. Those four children were later recognized and legitimized by the Church.
In addition, Gaunt gave his mistress several estates, and also provided her with a generous allowance. Since the relationship between Katherine and John of Gaunt caused public condemnation, in 1381 the Duke was forced to break their relationship. Katherine then settled in a rented house in Lincoln.
Despite the formal break, Katherine's relationship with her former lover and the rest of his family continued to be quite cordial. In 1387, she was made a Lady of the Garter by King Richard II, and shortly thereafter she became a member of the household of Mary de Bohun, wife of Henry Bolingbroke, eldest son and heir of John of Gaunt, who later became King of England under the name of Henry IV.
In the early 1390s, the love affair between Katherine and John of Gaunt resumed, and after the death of his second wife, the Duke unexpectedly married his mistress in 1396, which caused discontent among the English nobility. However, in the same year, a papal bull was received, recognizing the marriage as valid, and all the children born from the connection were legitimized. After the death of the Duke in 1399, Katherine retired to her rented house in Lincoln, where she died four years later. She was buried at Lincoln Cathedral.
Katherine and John of Gaunt's descendants, the Beaufort family, played a major role in the Wars of the Roses. Henry VII, who became King of England in 1485, derived his claim to the throne from his mother, Margaret Beaufort, who was a great-granddaughter of Gaunt and Swynford. His legal claim to the throne, therefore, was through a cognatic and previously illegitimate line. Henry VII's first action was to declare himself king "by right of conquest" retroactively from 21 August 1485, the day before his army defeated King Richard III at the Battle of Bosworth.
Through her son, John Beaufort, 1st Earl of Somerset, and her daughter, Joan Beaufort, Countess of Westmorland, Katherine became the ancestor of all English (and later British) kings since Edward IV.
Family
Katherine's father was Paon de Roet, a herald and, later, knight (who was "probably christened as Gilles"), who came to England in the entourage of Philippa of Hainaut, who married King Edward III. Its origin is not documented. Payne's family nickname was Roe (French: Roët). On this basis, it has been suggested that he was related to the powerful family of the Lords of Le Roeulx, who owned a lordship in the County of Hainaut, whose name was spelled differently: Rouet, Roëlt, Ruet. The origin of this genus has been traced back to Charlemagne. Their possessions were mainly concentrated around the city of Le Rœulx, located 8 miles northeast of Mons. They also included the towns of Roux (located 40 miles east of Mons) and Faurœulx (20 miles south). However, according to the historian Alison Weir, there is reason to doubt this version of Paon's origin: the chronicler Jean Froissart, who himself was from Hainaut, was most likely well aware of his origin, but does not write anything about his nobility. As Paon's father, he points to a certain Jean de Roët (died 1305), son of Huon de Roët. Froissart gives no titles for any of them. At the same time, Weir notes that this version cannot be completely discarded: Paon de Roet could indeed come from a younger line of the Le Roeulx family, since the spelling of the generic names Roeulx and Roët are quite similar and they could well be interchangeable. In addition, the name Gilles, which Paon received at baptism, was quite common in the family of the Lords of Le Roeulx.