Hundred Years' War

The Hundred Years' War was not a single continuous war but a sequence of armed conflicts, truces, and dynastic disputes fought between the House of Plantagenet (later Lancaster) of England and the House of Valois of France between 1337 and 1453. The proximate trigger was King Edward III of England's claim to the French throne following the death of Charles IV of France in 1328, combined with disputes over English-held fiefs in Gascony and French support for Scotland.

Historians typically divide the war into three phases:

• The Edwardian War (1337–1360), marked by decisive English victories at Crécy (1346) and Poitiers (1356), and concluded by the Treaty of Brétigny (1360), which ceded large territories in southwestern France to England in exchange for Edward III renouncing his claim to the French crown.
• The Caroline War (1369–1389), in which Charles V of France and his commander Bertrand du Guesclin recovered most of the lost territory through cautious Fabian tactics.
• The Lancastrian War (1415–1453), reopened by Henry V of England, whose victory at Agincourt (1415) and the Treaty of Troyes (1420) made him heir to the French throne. The tide turned after the intervention of Joan of Arc and the lifting of the siege of Orléans (1429), culminating in the French victory at Castillon (1453).

The war reshaped European state-building: it accelerated the decline of feudal levies in favor of standing armies, popularized the English longbow and later gunpowder artillery, and helped forge distinct English and French national identities. England lost all continental possessions except Calais (held until 1558). For IR students, the conflict is a canonical case study in dynastic versus territorial sovereignty, the emergence of the centralized fiscal-military state, and the role of legitimacy claims in protracted interstate war.