Catherine De Roet later Swynford, Duchess of Lancaster was born circa 1350 in Belgium to Payn De Roet (c1310-1380) and died 10 May 1403 Lincoln, Lincolnshire, England, United Kingdom of unspecified causes. She married Hugh Ottes Swynford (1340-1372) 1366 JL in England, United Kingdom. She married John of Gaunt, 1st Duke of Lancaster (1340-1399) 13 January 1396 JL in Westminster, Greater London, England, United Kingdom.
- Phillipa De Roet (c1348-aft1387)
|Offspring of Hugh Swynford and Catherine De Roet (1350-1403) ¢|
|Thomas Swynford (1367-1432)|
|Margaret Swynford (c1369-)|
|Blanche Swynford (c1370-)|
|Offspring of John of Gaunt, 1st Duke of Lancaster and Catherine De Roet (1350-1403)|
|John Beaufort, 1st Earl of Somerset (c1373-1410)||1371||16 March 1409||Margaret Holland (1385-1439)|
|Henry Cardinal Beaufort, Bishop of Winchester (1375-1447)|
|Thomas Beaufort, 1st Duke of Exeter (1377-1426)|
|Joan Beaufort (1379-1440)||1379 Château de Beaufort, Haute-Loire, France||13 November 1440 Howden, Yorkshire, England||Robert, 3rd Baron Ferrers of Wemme (c1373-1396) Robert, 3rd Baron Ferrers of Wemme (c1373-1396) Ralph de Neville, 1st Earl of Westmorland (c1364-1425)|
"[Swynford's children] were:
Although Thomas married twice, Hugh apparently had no grandchildren.
In 1846 Thomas Stapleton suggested that there was a further daughter named Dorothy Swynford, born c. 1366, who married Thomas Thimelby of Poolham near Horncastle, Lincolnshire, Sheriff of Lincolnshire in 1380, but there is no current evidence to support this claim.