Thomas Beaufort, Duke of Exeter (b. 1377)
Thomas Beaufort, Duke of Exeter (c. January 1377 – 31 December 1426) was an English military commander during the Hundred Years' War, and briefly Chancellor of England. He was the third of the four children born to John of Gaunt, Duke of Lancaster, and his mistress Katherine Swynford. To overcome their problematic parentage, his parents were married in 1396, and he and his siblings were legitimated in 1390 and again in 1397. He married the daughter of Sir Thomas Neville (died 1387) of Hornby, Margaret Neville (born c. 1384), who bore him one son, Henry Beaufort. However, the child died young.