John of Gaunt's children

John of Gaunt (1340-1399) had fourteen children.

In 1359 John's mistress, Marie de Saint Hilaire of Hainaut gave birth to a daughter.

• Blanche (1359-c1388) married Sir Thomas Morieux (1355-1387).  Sir Thomas Morieux, constable of the Tower of London died during the Castilian campaign. Blanche and Thomas had no children.

On 19 May 1359 John married his third cousin, Blanche (1345-1369), daughter of the 1st Duke of Lancaster. John and Blanche had seven children.

• Philippa (1360-1415) married King John I of Portugal (1357-1433)
• John (1362-1365)
• Elizabeth (1364-1426) married in 1380 John Hastings, 3rd Earl of Pembroke (1372-1389) [marriage annulled in 1383]; in 1386 John Holland 1st Duke of Exeter (1350-1400); Sir John Cornwall 1st Baron of Fanhope (c1364-1423)
• Edward (born and died 1365)
• John (1366-1367)
• Henry of Bolingbroke (1367-1413) married (c1381) Mary de Bohun (1369-1394); in 1403 Joanna of Navarre (1368-1437). Henry became Henry IV of England in 1399
• Isabel (born and died 1368)

In 1371 John married Constance of Castile daughter of King Peter of Castile. John and Constance had two children

• Catherine (1372-1418) married in 1388 King Henry III of Castile (1379-1406)
• John (1374-1375)

In 1396 John married Katherine Swynford (Katherine de Roet) (1350-1403). Katherine had been John's mistress for many years and they had four children.

• John Beaufort (1373-1409) 1st Earl of Somerset in 1397 married Margaret Holland (1385-1439)
• Henry Beaufort (1375-1447) He became Bishop of Winchester
• Thomas Beaufort (1377-1427) Duke of Exeter married Margaret Neville 
• Joan Beaufort (1379-1440) married in 1391 Robert Ferrers, 5th Baron Boteler and Wem (1373-1396); in 1396 Ralph Neville 1st Earl of Westmoreland (1364-1425)

Further posts will look at the careers of some of these children and their families who were influential in England and other parts of Europe for many years.