| Male John de Beaufort, 1st Marquess of Somerset and 1st Marquess of Dorset, later only 1st Earl of Somerset, KG |
| Birth | 1371 | Lincolnshire, England |
| Death | 16 March 1410 | London, City of London, Greater London, England |
| Burial | Canterbury, City of Canterbury, Kent, England |
|
| Marriage | ||
| Father | John Gaunt Plantagenet | F3399 Group Sheet | |
| Mother | Constance of Castile, Duchess of Lancaster | F3399 Group Sheet | |
| Female Margaret Holland, Duchess Of Clarence, Lady Companions of the Garter |
| Birth | 1385 | |
| Death | 31 Dec 1439 | |
| Burial | ||
| Other Spouse | Thomas of Lancaster, Duke of Clarence (1387–1421) | F511 | |
| Marriage | ||
| Father | Thomas Holland, 2nd Earl of Kent KG | F212 Group Sheet | |
| Mother | Alice FitzAlan, Lady | F212 Group Sheet | |
| Female Joan Beaufort, Lady, Queen of Scots |
| Birth | Abt. 1404 | |
| Death | 15 Jul 1445 | |
| Burial | ||
| Spouse | James I Stewart, The Black Knight Of Lorn, King of Scotland | F3159 | |
| Marriage | ||
| Male John de Beaufort, 1st Duke of Somerset, 3rd Earl of Somerset, KG |
| Birth | 25 Mar 1404 | |
| Death | 30 May 1444 | |
| Burial | ||
| Spouse | Margaret Beauchamp, of Bletso | F2092 | |
| Marriage | ||
| Male Edmund de Beaufort, 2nd Duke of Somerset, 4th Earl of Somerset, 1st Earl of Dorset, 1st Marquess of Dorset styled 1st Count of Mortain,KG |
| Birth | 1406 | |
| Death | 22 May 1455 | |
| Burial |
| Female Margaret de Beaufort, Countess of Devon |
| Birth | Abt. 1409 | |
| Death | 1449 | |
| Burial | ||
| Spouse | Thomas de Courtenay, 5th\13th Earl of Devon (3 May 1414 – 3 February 1458 | F3362 | |
| Marriage | ||