Beauchamp's father, a near kinsman of the Earls of Warwick, had been a royal retainer under Richard II, Henry IV, and Henry V. On his father's death he also entered the king's service in the Hundred Years' War. During the 1420s Beauchamp served under the Duke of Bedford in medieval France : he was captain of Pont-de-l'Arche in 1422–1429, lieutenant of Rouen Castle in 1429, a participant in the Maine–Anjou campaigns, and a counsellor to the duke and member of his household.
Beauchamp's father, a close family member of the Earls of Warwick, had been a royal servant under Richard II, Henry IV, and Henry V. Upon his father's demise, Beauchamp also joined the king's service in the Hundred Years' War. In the 1420s Beauchamp served under the Duke of Bedford in medieval France: he was commander of Pont-de-l'Arche from 1422 to 1429, lieutenant of Rouen Castle in 1429, a participant in the Maine–Anjou campaigns, and an advisor to the duke and member of his household.