The Hundred Years' War was a series of conflicts fought between England and France from 1337 to 1453. The war began over territorial disputes and claims to the French throne, primarily involving the English monarchs' rights to land in France. Key battles included Crécy, Poitiers, and Agincourt, where the English longbowmen played a significant role. The war saw the rise of national identities in both countries and significant changes in military tactics. It ended with the French victory, leading to the expulsion of the English from most of their territories in France, except for Calais.