made lieutenant of England when his brother invaded France in 1415, during the Hundred Years' War. In 1416 John commanded the English fleet that defeated the French at the mouth of the Seine River. In 1422, after his brother's death, John was designated protector and defender of the kingdom for the young King Henry VI. Transferring his duties in England to his brother Humphrey, duke of Gloucester, John took over the conduct of English affairs in France in order to consolidate the English position against further French opposition. After reaffirming the alliance made in 1420 by Henry V with Philip the Good, duke of Burgundy, John and Philip in 1424 gained a victory at Verneuil, France, over the Dauphin, later King Charles VII of France. In 1429 John's forces were defeated by the French heroine Joan of Arc at the siege of Orléans and the subsequent Battle of Patay. Two years later, when Joan, who had been captured by the Burgundians, was turned over to the English, John allowed her to be burned at the stake as a heretic. Thereafter John's plans for the conquest of France were frustrated by the defection to France of Philip the Good.