thumb|150px|Arms of the Beaufort family, legitimised descendants of John of Gaunt: Royal arms of King Edward III within a [[bordure compony argent and azure]]

Joan Beaufort ( 1379 – 13 November 1440) was the youngest of the four legitimised children and only daughter of John of Gaunt, 1st Duke of Lancaster (third surviving son of King Edward III), by his mistress, later wife, Katherine de Roet. Joan married Ralph de Neville, 1st Earl of Westmorland and in her widowhood became a powerful landowner in the north of England, as countess of Westmorland. Joan was grandmother to kings Edward IV and Richard III, and great-great grandmother to Henry VIII.

Early life

The year and place of Joan's birth is unknown. She may have been born at Kettlethorpe in Lincolnshire, the seat of the Swynford family, or at Pleshey in Essex, the home of Joan Fitzalan, Countess of Hereford. The usual date given for Joan's birth is 1379, as wine was ordered by John of Gaunt to be sent with all speed to Kettlethorpe in that year and he dated a couple of documents at that time from Kettlethorpe; thus, Joan's father may have been present for her birth or arrived shortly thereafter.<!-- I will look up the references in his Registers when I get the chance. --> Alison Weir, however, believes 1377 may be more accurate. Joan may have been named after Joan of Kent, at the time of her birth Dowager Princess of Wales. She married John de Greystoke, 4th Baron Greystoke (1389–1436) on 28 October 1407 in Greystoke Castle, Greystoke, Cumberland, and had issue. She is buried at Black Friars Church, York.

  • Mary or Margery (1394 – 25 January 1457/1458). She married her stepbrother, Sir Ralph Neville, son of Ralph Neville, 1st Earl of Westmoreland, before 1411 in Oversley, Warwickshire and had issue.

Second marriage

thumb|150px|Arms of Neville: [[Gules, a saltire argent. Borne by Joan's progeny but with difference a of label three points compony of Beaufort (i.e. compony argent and azure)]]

thumb|[[Richard Neville, 5th Earl of Salisbury, who displays the arms of Neville (tinctures transposed in error) with a label compony of Beaufort for difference. Salisbury Roll of Arms]]

In November 1396 Joan married, secondly, to the recently widowed Ralph Neville, 1st Earl of Westmorland (d. 1425), Joan Beaufort and Ralph Neville had the following 14 children: Although that king had created Ralph as the first Earl of Westmorland, Ralph sided with Joan's half-brother Henry Bolingbroke, who deposed Richard in 1399 and assumed the throne as King Henry IV. Joan and Ralph were granted numerous offices, lands, wardships and pensions under Henry IV. By the time of her death, Joan was the mother of an earl, three barons, a countess, three duchesses and a bishop. In about 1430 Joan and her family were depicted by Pol de Limbourg in the Neville Hours. and was buried beside her mother in Lincoln Cathedral.