Hundred Years' War (1415–53)
The Lancastrian War was the third and final phase of the Anglo-French Hundred Years' War. It lasted from 1415, when King Henry V of England invaded Normandy, to 1453, when the English lost Bordeaux. It followed a long period of peace from the end of the Caroline War in 1389. The phase was named after the House of Lancaster, the ruling house of the Kingdom of England, to which Henry V belonged.
Hundred Years' War
France was an ally of the Kingdom of Scotland as English kings had for some time tried to subjugate the area. In 1295, a treaty was signed between France and Scotland during the reign of Philip the Fair. Charles IV formally renewed the treaty in 1326, promising Scotland that France would support the Scots if England invaded their country. Similarly, France would have Scotland's support if its own kingdom was attacked. Edward could not succeed in his plans for Scotland if the Scots could count on French support.