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.
House of Valois
Because diplomacy and negotiation had failed, Edward III would have to back his claims with force to obtain the French throne. For a few years, England and France maintained an uneasy peace. Eventually, an escalation of conflict between the two kings led to the confiscation of the duchy of Aquitaine (1337). Instead of paying homage to the French king, as his ancestors had done, Edward claimed that he was the rightful King of France. These events helped launch the Hundred Years' War (1337-1453) between England and France. Though England failed to win that prolonged conflict, English and British Monarchs until the late 18th Century continued to maintain, at least formally, a claim to the French throne.