Hundred Years' War
Historians commonly divide the war into three phases separated by truces: the Edwardian War (1337–1360), the Caroline War (1369–1389), and the Lancastrian War (1415–1453). Local conflicts in neighbouring areas, which were contemporarily related to the war, including the War of the Breton Succession (1341–1365), the Castilian Civil War (1366–1369), the War of the Two Peters (1356–1369) in Aragon, and the 1383–85 crisis in Portugal, were availed by the parties to advance their agendas. Later historians adopted the term "Hundred Years' War" as a historiographical periodisation to encompass all of these events, thus constructing the longest military conflict in European history.
John II of France
In 1355, the Hundred Years' War flared up again. In July 1356, Edward, the Black Prince, son of Edward III of England, took an army on a great "chevauchée" through France. John pursued him with an army of his own. In September the two forces met a few miles southeast of Poitiers.