The following table illustrates the relationships of the various members of the English royal family.
| Edward III (reigned 1327–1377) | |||||||||||||||||||
| Edward (the Black Prince) | William (died in infancy) | Lionel (Duke of Clarence) | John of Gaunt (Duke of Lancaster) | Edmund (Duke of York) | |||||||||||||||
| Richard II (reigned 1377–1399) | Philippa (married Edmund Mortimer, Earl of March) | Henry IV (reigned 1399–1414) | Edward (Duke of York; slain at Agincourt) | Richard (Earl of Cambridge; beheaded 1415) | |||||||||||||||
| Roger Mortimer (Earl of March) | Henry V (reigned 1414–1422) | John (Duke of Bedford) | Humphrey (Duke of Gloucester) | Richard (Duke of York) | |||||||||||||||
| Edmund Mortimer (Earl of March) | Anne (married Richard, Earl of Cambridge) | Henry VI | |||||||||||||||||
| Richard (Duke of York) | |||||||||||||||||||
Somerset (John, 1st Duke of Somerset, 1403–1444) was the grandson of John of Gaunt, his father and the Bishop of Winchester (cf. III. i. 42) being both illegitimate sons of that prince.
