The Duchess Constance dying in 1394, John espoused, in 1396, Catherine, daughter of Sir Paine Roet, Guienne King of Arms, and widow of Sir Hugh Swynford, a knight of Lincolnshire. This lady had been of the household of the Duchess Blanche and charged with the education of the ladies Philippa and Elizabeth during their minority.

Catherine era su amante de mucho tiempo.

His issue, before his marriage to his third consort, Catherine Swynford, were legitimated by Act of Parliament, 9th February 1397. They were all surnamed "De Beaufort," having been born at Beaufort Castle in France, which had devolved to the Huse of Lancaster by the marriage of Blanche of Artois with Edmund, Earl of Lancaster. They were:

1. John Beaufort, Earl of Somerset and Marquis of Dorset, KG
2. Henry Beaufort, Bishop of Lincoln, afterwards of Winchester, and, at length, Cardinal and Chancellor of England
3. Thomas Beaufort, Duke of Exeter, KG
4. Joan Beaufort, married, firstly, to Sir Robert Ferrers of Worn and Oversley; and, secondly, to Ralph Neville, Earl of Westmorland. Her grandsons included Richard, Earl of Warwick 'the Kingmaker,' Kings Edward IV and Richard III.

Edited from George Frederick Beltz's "Memorials of the Most Noble Order of the Garter" (1861)

a knight of Lincolnshire