When the direct line of France's Capetian dynasty went extinct in 1328, the English king Edward III pressed a claim to the French throne through his mother. The Valois family was crowned instead; but the real core of the dispute was the long feudal entanglement between the two crowns — above all, the English kings' large holdings in France, such as Gascony and Aquitaine, for which they were technically vassals of the French king. In 1337 Philip VI declared Aquitaine confiscated, Edward renewed his royal claim, and what historians would later call the 'Hundred Years' War' began as an intermittent chain of campaigns.

The military face of the war shook the established European order. At Crécy (1346) English longbowmen broke the French heavy cavalry; at Poitiers (1356) King John II of France was captured; Agincourt (1415) again showed armoured knights bogged in mud and helpless against massed archery. From the late 14th century, cannon and gunpowder began to shift the balance of siege warfare. The Black Death (from 1347 onward) drained both sides of population and finance, so the war turned from quick conquests into long attritional decay. Striking power gradually moved to professional paid soldiery — the military monopoly of the knightly class was ending.

In 1429 Joan of Arc broke the siege of Orléans and saw Charles VII crowned at Reims, giving the French resistance a symbolic axis; in 1431 she was burned by an English-controlled church court. As a historian one must separate hagiography from documentation: her trial records and the 1456 nullification proceedings are well attested, but much of the miraculous narrative built around her belongs to later centuries. In 1453 at Castillon, France defeated the last great English field army; England lost almost all of its continental territory, retaining only Calais (until 1558).

The war's lasting result reached far beyond redrawn borders. In France the crown established central control over permanent taxation and a standing army; royal identity slowly evolved towards an ethno-linguistic sense of 'nation'. England withdrew from the continent and slid into the Wars of the Roses. Read at scale, the Hundred Years' War is the long closing act of the feudal-chivalric order in Europe and the rise of the centralised monarchy–gunpowder–infantry triad that would dominate the following centuries.