Who commanded England's armies in France during a critical phase of the Hundred Years' War?

John of Lancaster, 1st Duke of Bedford KG (20 June 1389 – 14 September 1435) was a medieval English prince, general and statesman who commanded England's armies in France during a critical phase of the Hundred Years' War. Bedford was the third son of King Henry IV of England, brother to Henry V, and acted as regent of France for his nephew Henry VI. Despite his military and administrative talent, the situation in France had severely deteriorated by the time of his death.

Bedford was a capable administrator and soldier, and his effective management of the war brought the English to the height of their power in France. However, difficulties mounted after the arrival of Joan of Arc, and his efforts were further thwarted by political divisions at home and the waverings of England's key ally, the duchy of Burgundy. In the last years of Bedford's life, the conflict devolved into a war of attrition, and he became increasingly unable to gather the necessary funds to prosecute the conflict.

Bedford died during the congress of Arras in 1435, just as Burgundy was preparing to abandon the English cause and conclude a separate peace with Charles VII of France.