(Born November  25, 1350 – Died May 10, 1403). Daughter of Payne de Roet. Sister of Philippa Chaucer, the wife of Geoffrey Chaucer. Married to Hugh Swynford and John of Gaunt, 1st Duke of Lancaster. Mother of the Beauforts as well as 3 children with Hugh Swynford.

Katherine was probably born on or around November 25, 1350 to Payne de Roet, a herald and later a knight. We don’t know much about her early life.  Katherine was appointed governess to watch over the children of John of Gaunt and Blanche of Lancaster in 1365. In 1367, she married Hugh Swynford, a knight, and they had 3 children; Blanche, Thomas and Margaret Swynford.

Hugh Swynford and Blanche of Lancaster would both die in 1371, the same year that rumors began that Katherine and John were having an affair. John quickly silenced those rumors by marrying Constance of Castile later the same year. In 1372 Katherine’s position in John’s household got better and by 1373, their first child John, was born. They would have 4 children; John, Henry, Thomas and Joan.They would adopt the last name Beaufort in honor of their father’s lost of his lordship of Anjou.

During the 1380’s, Katherine left court so John could repair his reputation after the Peasants’ Revolt. When Constance died in 1394, everything changed for the couple. They were married in 1396 and their children became legitimate, however they were banned from the line of succession for the throne of England. John would die on February 3, 1399, leaving Katherine a widow yet again. Katherine would die on May 10, 1403.

Her children with John of Gaunt, the Beauforts and their children, would change English history forever.