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.
Hundred Years' War
In 1366 there was a civil war of succession in Castile (part of modern Spain). The forces of the ruler Peter of Castile were pitched against those of his half-brother Henry of Trastámara. The English crown supported Peter; the French supported Henry. French forces were led by Bertrand du Guesclin, a Breton, who rose from relatively humble beginnings to prominence as one of France's war leaders. Charles V provided a force of 12,000, with du Guesclin at their head, to support Trastámara in his invasion of Castile.