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Why did the Hundred Years’ War begin between England and France?

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Medieval illustration of the Battle of Crecy shows armored soldiers fighting with swords, shields, and bows as mounted knights and banners fill the background. — Hundred Years’ War Image depicting the Battle of Crécy, during the Hundred Years' War, in which Edward III of England defeated Philip VI of France on August 26, 1346.

The Hundred Years’ War was not caused by a single event but by a combination of long-standing territorial disputes and a crisis of royal succession.1

Territorial Disputes

The conflict was rooted in the complex political relationship between England and France dating back to the 12th century. English kings held fiefs in France, such as the duchy of Guyenne, making them vassals to the French crown. This arrangement led to frequent friction, as French monarchs often intervened in the administration of these lands, prompting appeals from local malcontents to the Parlement of Paris.21

Succession Crisis

A major turning point occurred in 1328 when the French king Charles IV died without a male heir. Edward III of England claimed the throne through his mother, but an assembly of magnates chose Philip VI of the House of Valois.3

Outbreak of War

Tensions escalated as Philip VI supported the Scots and sought to consolidate control over English-held territories. The war is conventionally dated to May 24, 1337, when Philip VI declared the duchy of Guyenne confiscated, leading Edward III to formally assert his claim to the French throne.341