The Hundred Years War came about as tensions rose between England and France. Since William the Conquerer ruled England and Normandy in 1066, English holdings in France had grown. While the name suggests the war lasted 100 years, fighting actually occured on and off between 1337AD and 1453AD. The primary cause of fighting was over the rightful ruler of France. At the beginning of the war, King Charles IV of France died with no children. Two main claims were made on the throne. That of Edward III of England and Philip III of France.
Fighting continued until 1380 where internal power struggles in both countries created an uncertain peace. This ended in 1413 as the new English king Henry V took advantage of French discord. By 1422, England and some French allies controlled Aquitaine and the entire French North, including Paris.
The tides again turned in 1429 as French forces took advantage of the War of the Roses causing discord in England. Equally, English allies in France realised the English could not control an area the size of France and switched sides. By 1453, the only remaining English territory in France was Calais.
Historians widely regard this conflict as a turning point in European politics. A variety of English frustrations led to a concentration on internal development. Meanwhile, French victory unified the country and meant it became more than a loosely grouped number of independent states.
