Although only twenty years old, John distinguished himself at the siege of Harfleur and the battle of Agincourt leading a retinue of some 20 men-at.-arms and 60 foot archers. As a result, he was restored in blood, regained the earldom of Huntingdon and was made a Knight of the Garter the next year. He was to go on to become one of the English commanders in the latter part of the HYW, being made Lord High Admiral of England in 1435 and regaining the Dukedom of Exeter in 1439, the same year he was made the King's lieutenant in Aquitaine.
On his death, his son Henry became Duke of Exeter, but two of his natural sons (the 'bastards of Exeter') were to be active members of the Lancastrian cause, but are believed to have fallen at Towton (1461). I think they may well make an appearance in my planned WotR army ;-)