Issue of Edward III of England – 3 February 1399), 1st Duke of Lancaster, fourth son. From the marriage of John of Gaunt and Blanche of Lancaster, daughter and heiress of the Duke of Lancaster, descended legitimate male heirs, the Lancasters (King Henry IV (1399-1413), who as Henry of Bolingbroke in 1399 deposed his first cousin King Richard II (1377-1399), and was followed by his son King Henry V(1413-1422) and the latter's son King Henry VI (1422-1471). This line ended in 1471 when King Henry VI's son Edward of Westminster, Prince of Wales was killed at the Battle of Tewkesbury and when he himself was deposed
Edmund Beaufort (died 1471) due to occasional insanity she assisted in his duties, Somerset was unenthusiastic over the reconciliation and made little effort to co-operate. In fact his failure to hold London against Edward IV was a decisive moment, leading to the Battle of Barnet (14 April 1471) and the death of Warwick. Some sources say he was present at Barnet, but this is an error. Fleeing west towards Wales to seek help from Jasper Tudor, but halted by the Yorkist army at the Battle of Tewkesbury (4 May 1471), he commanded the van of the Lancastrian army at the battle. His position was