Hundred Years' War

Series of conflicts between England and France in 1337–1453. Its causes were the French claim (as their fief) to Gascony in southwest France, held by the English kings, and medieval trade rivalries in Flanders. Medieval England and France had a long history of war before 1337, and the Hundred Years' War has sometimes been interpreted as merely an intensification of these struggles. It was caused by fears of French intervention in Scotland, which the English were trying to subdue, and by the claim of England's Edward III (through his mother Isabella, daughter of Philip IV of France) to the crown of France.

Edward began by attempting to regain territories held by his Angevin ancestors, Henry II and Richard I, in northwest France. At first the English gained some remarkable victories, including the sea‐battle of Sluys (1340), and the Battle of Crécy (1346). Calais surrendered in 1347. John II of France (reigned 1350–64) continued to fight, but he was defeated and captured by Edward the Black Prince, at the Battle of Poitiers (1356), and English gains were recognized by the Treaty of Brétigny (1360). However, under Charles (V) the Wise, France regained ground, particularly thanks to the efforts of the commander Bertrand du Guesclin, who gained control of nearly all the English possessions during the 1370s.

Henry V of England, renewing the war, won the Battle of Agincourt (1415), overran northern France, and formed a powerful alliance with the duchy of Burgundy. Charles (VI) the Mad was forced to sign the Treaty of Troyes in 1420. By this treaty Henry V became regent of France, and in 1422 Henry V's young son Henry (later Henry VI) was proclaimed king of France in Paris.

However, fighting abroad, England was limited to massive campaigns marked by chevauchées– large‐scale forays through France, burning and looting. English success at Poitiers and Agincourt also owed much to the clever tactical use of English archers with their longbows. Conversely, the French – helped by improvements to French cannon by the brothers Bureau – were able to exert steady resistance, and slowly the English were driven back.

England's Burgundian alliance collapsed in 1435, and the French were further encouraged by the victories of Joan of Arc, particularly at the battle of Orléans when she defeated the English siege in 1429. Shortly afterwards Charles VII was crowned at Reims and began to establish his authority. The French won significant battles, including the Battle of Formigny (1450) and the Battle of Castillon (1453). The war ended after the English defeat at Castillon, although there was no final treaty, and Calais alone remained in the hands of the English crown.

For further details of the Hundred Years' War, see:France: history to 1515.