Hundred Years’ War 1337–1453: Why Did England Win the Famous Battles but Lose the War?

The Regimental Record · Medieval Kingdoms · Campaign Investigation · 1337–1453

The Hundred Years’ War contains some of England’s most celebrated battlefield victories: Crécy in 1346, Poitiers in 1356 and Agincourt in 1415. Yet by the middle of the fifteenth century the English crown had lost almost all of the territory those victories were supposed to secure.

That apparent contradiction is the best way into the war. How could England repeatedly win spectacular battles and still lose the larger struggle?

The answer is not that the victories were meaningless. They changed diplomacy, captured kings, opened ports and created moments of extraordinary English leverage. The problem is that battlefield success had to be converted into occupation, taxation, garrisons, alliances, legitimacy and durable political control. Over more than a century, France proved better able to recover from defeat than England was able to turn victory into a permanent settlement.

First problem: there was no single uninterrupted “Hundred Years’ War”

The label is modern shorthand. Fighting began in 1337 and the conventional endpoint is 1453, but the period included truces, peace settlements, civil conflict and long stretches in which the scale of campaigning changed dramatically.

It is more useful to think in phases: Edward III’s early war; the crises created by Crécy and Poitiers; French recovery under Charles V; a later lull; Henry V’s renewed conquest; the dual-monarchy crisis after 1422; and the final French reconquest culminating in Normandy and Gascony.

Iron Regiment confidence call: treating 1337–1453 as one continuous war is low confidence. Treating it as a connected dynastic and territorial conflict fought in changing phases is high confidence.

Why the war began

The dispute mixed feudal law, sovereignty, dynastic succession and strategic rivalry. English kings held lands in France and were therefore, in one capacity, vassals of the French king. That relationship created repeated conflict over homage, jurisdiction and control of Aquitaine.

The succession crisis of 1328 added another layer. When Charles IV of France died without a surviving son, Edward III of England had a claim through his mother, Isabella of France. The French political elite instead accepted Philip VI of Valois. Edward did not immediately launch a war simply because a crown had been “stolen”; the royal claim became one weapon inside a wider struggle over sovereignty and territory.

The Channel, Flanders and the problem of access

England could not fight effectively in France without moving armies, horses, money and supplies across the Channel. Naval security therefore mattered from the beginning. The victory at Sluys in 1340 damaged French naval capacity and helped protect English movement, but it did not solve the war.

Flanders mattered because of trade, politics and geography. Alliances in the Low Countries could give Edward pressure points against the French monarchy, but continental alliances were expensive and unstable.

Edward III’s strategic method: chevauchée and pressure

Edward’s armies frequently used the chevauchée: fast-moving campaigns that devastated crops, towns and estates. The aim was not random destruction. It attacked the tax base, challenged the French king’s ability to protect his subjects and attempted to force battle or political concession.

Civilians paid heavily for that strategy. A campaign could be successful in military terms while being catastrophic for the communities crossed by it.

Crécy 1346: decisive battle, limited strategic answer

Edward’s 1346 campaign crossed Normandy, forced the Somme and stood to fight near Crécy. The English defensive system combined large numbers of archers with dismounted men-at-arms, disciplined command and a prepared position. The French army suffered a severe defeat.

The longbow was crucial, but it was not a magic weapon that independently defeated feudal France. For the full evidence audit—including the modern dispute over the exact battlefield—read Crécy 1346: Did the Longbow Really Win the Battle?.

The strategic exploitation came at Calais. Edward besieged and captured the port in 1347. Calais became a long-term English bridgehead and commercial gateway. That was a durable result in a way that battlefield prestige alone was not.

The Black Death changes the war

The plague that struck western Europe from 1348 transformed demography, labour, taxation and military recruitment. It interrupted campaigning and altered the societies that sustained the war. It did not end Anglo-French rivalry.

Poitiers 1356: a king captured

The Black Prince’s campaign in 1356 ended with another extraordinary English victory at Poitiers. King John II of France was captured. Few battlefield outcomes could have created greater diplomatic leverage.

Yet even the capture of the French king did not make permanent English victory inevitable. France endured political disorder, negotiated, raised money and eventually rebuilt its military position.

Brétigny 1360: England reaches its high-water mark

The Treaty of Brétigny gave Edward III major territorial gains and appeared to transform battlefield success into a political settlement. But enforcing sovereignty over large French territories was more difficult than winning them on parchment.

Local loyalties, taxation, legal authority and the cost of garrisons all mattered. A medieval conquest survived only if administration survived with it.

Charles V and the French recovery

Under Charles V, France increasingly avoided the type of large pitched battle that had produced Crécy and Poitiers. Commanders such as Bertrand du Guesclin used sieges, local operations and pressure against English-held territory.

This was not cowardice or an admission that English tactical superiority could never be overcome. It was adaptation. France did not have to defeat every English army in an Agincourt-style battle to recover towns and provinces.

By the end of Edward III’s reign, much of the territory gained earlier had been lost.

Why famous victories did not equal permanent conquest

• Occupation cost money. Castles, towns and garrisons required permanent expenditure.
• Local legitimacy mattered. Subjects had to be taxed, governed and persuaded—or coerced—to accept new rulers.
• France had greater demographic depth. Catastrophic defeats did not destroy the kingdom’s capacity to recover indefinitely.
• English coalitions were fragile. Continental allies pursued their own interests.
• The French could change the type of war. Avoiding unfavourable pitched battle reduced the value of England’s strongest battlefield system.

The war changes again: French civil conflict

By the early fifteenth century the French monarchy was weakened by the illness of Charles VI and conflict between Armagnac and Burgundian factions. The murder of Louis of Orléans in 1407 and later killing of John the Fearless in 1419 deepened the division.

That internal fracture created the strategic opportunity Henry V exploited.

Henry V and the 1415 campaign

Henry invaded Normandy in 1415 and captured Harfleur after a difficult siege. Disease reduced his army before the march towards Calais. The campaign ended at Agincourt, where a larger French force attacked through restricted, rain-soaked ground and suffered a catastrophic defeat.

The longbow mattered, but so did terrain, formation depth, mud, command and the transition from missile fighting to close combat. Read the full investigation: Agincourt 1415: Was It Really the Longbow That Won?.

Agincourt did not conquer France

Agincourt created prestige and weakened a section of the French military elite, but Henry still had to return with armies, capture towns and establish control. His later conquest of Normandy involved sieges, garrisons and administration on a scale the one-day battle narrative can obscure.

This is one of the war’s central lessons: the spectacular battle attracts memory; the occupation determines whether victory lasts.

The Treaty of Troyes and the dual monarchy

In 1420 the Treaty of Troyes recognised Henry V as heir to Charles VI and arranged his marriage to Catherine of Valois. The settlement excluded the Dauphin Charles.

Had Henry lived long enough to inherit the French crown personally, the political story might have developed differently. Instead Henry V and Charles VI both died in 1422. Henry VI, still an infant, became king of England and was proclaimed king of France by the English-Burgundian regime.

Orléans and Joan of Arc

The siege of Orléans in 1428–29 became a turning point. Joan of Arc arrived within a wider French recovery and helped transform morale and political momentum. The subsequent campaign enabled Charles VII to be crowned at Reims.

Joan’s role was important, but “Joan saved France by herself” is another single-person explanation that hides armies, commanders, finance, local politics and the changing Burgundian relationship.

Joan’s capture and execution

Joan was captured by Burgundian forces in 1430, transferred to the English and tried at Rouen. She was executed in 1431. Her death did not reverse the French recovery.

That alone shows the danger of making the entire war depend on one charismatic figure.

Burgundy: the alliance that changed the balance

The English position depended heavily on Burgundian cooperation. In 1435 the Treaty of Arras reconciled Philip the Good of Burgundy with Charles VII.

The shift did not instantly eject England from France, but it removed a central pillar of the English political system. France could increasingly concentrate on English-held territory without a major civil-war front dividing the kingdom.

Iron Regiment confidence call: Burgundy’s change of alignment was a major strategic factor — high confidence. Claiming it alone caused English defeat — low confidence.

Charles VII’s military recovery

French recovery in the 1440s involved stronger royal institutions, more regular military formations and increasingly effective artillery. The compagnies d’ordonnance and reforms in taxation helped the monarchy sustain forces more consistently.

Artillery mattered especially in siege warfare. English-held towns and fortresses could be reduced more rapidly once French guns, engineers and logistics improved.

Formigny 1450: Normandy lost

At Formigny, an English field army was defeated during the French reconquest of Normandy. Artillery influenced the action, but the battle should not be reduced to “cannon replaced longbow.” Cavalry movement, reinforcement and the broader operational situation all mattered.

Normandy then collapsed as an English possession.

Castillon 1453: the conventional end

The final major battle came at Castillon in Gascony. French forces under Jean Bureau constructed a fortified artillery position. The English army under John Talbot attacked and was defeated; Talbot was killed.

Castillon is often presented as the battle in which artillery ended the Middle Ages. That is too neat. Gunpowder had been present in European warfare for generations, longbows did not instantly disappear, and military systems do not change on one afternoon.

What Castillon did demonstrate was the growing ability of the French monarchy to combine field fortification, artillery, infantry and state resources in a way that England could no longer match in France.

Did the war actually end in 1453?

There was no grand peace treaty in 1453 formally closing a conflict called “the Hundred Years’ War.” The conventional endpoint reflects the loss of Bordeaux and the effective collapse of England’s territorial position except Calais.

English kings continued to claim the French crown for centuries. The military reality had nevertheless changed decisively.

Iron Standard evidence audit

Competing explanations: why England lost

The technology explanation says England dominated while the longbow was supreme and lost when French artillery became superior. This is attractive and incomplete. Both weapons existed within larger military systems.

The manpower explanation stresses France’s greater demographic and fiscal depth. This matters, but French governments still had to convert resources into usable armies and political control.

The institutional explanation points to Charles VII’s stronger taxation, regular troops and artillery administration. This is one of the strongest explanations for the final phase.

The alliance explanation gives major weight to Burgundy. English power in northern France was far easier to maintain while France remained politically divided.

The occupation explanation asks the simplest question: could England permanently pay for and govern large French territories? Repeatedly, the answer was no.

Iron Regiment’s current judgement is that England lost because France survived the great battlefield disasters, repaired its political divisions and built enough institutional and military capacity to turn superior strategic depth into reconquest.

Source genealogy: how we know what happened

Royal accounts, tax records, indentures, muster material and administrative documents are often stronger than chronicles for reconstructing armies, finance and occupation. They are incomplete but less dependent on dramatic storytelling.

Jean le Bel, Froissart, Monstrelet and other chroniclers preserve extraordinary detail and near-contemporary memory. They wrote for audiences, patrons and political communities and must be compared rather than read as neutral transcripts.

The Medieval Soldier project and modern archival databases allow historians to reconstruct individuals, retinues and campaign service more systematically than older narrative histories could.

Battlefield archaeology and topographical work can test locations and physical claims but are uneven across the war. Crécy’s exact field, for example, remains disputed.

Later national memory made Crécy, Agincourt, Joan of Arc and Castillon symbols of English or French identity. Memory is evidence for commemoration, not automatically for battlefield fact.

What would change our mind?

• Newly identified muster, financial or garrison records materially changing estimates of English occupation capacity.
• New Burgundian or French diplomatic material altering understanding of the 1435 political realignment.
• Battlefield archaeology that changes the accepted tactical interpretation of major engagements such as Crécy, Agincourt, Formigny or Castillon.
• New quantitative work demonstrating that demographic or fiscal assumptions about English and French war-making capacity are substantially wrong.

Campaign chronology

Related Regimental Record investigations

• Crécy 1346: Did the Longbow Really Win the Battle?
• The 1415 Campaign: Harfleur, the March to Calais and the Road to Agincourt
• Agincourt 1415: Was It Really the Longbow That Won?

Sources and further reading

• The Medieval Soldier project — archival databases and research on English and French military service.
• Jean le Bel, Chronique.
• Jean Froissart, Chroniques.
• Enguerrand de Monstrelet, Chroniques.
• Jonathan Sumption, The Hundred Years War series.
• Anne Curry, works on Agincourt and the Hundred Years’ War.
• Christopher Allmand, The Hundred Years War.
• Clifford J. Rogers, studies of late-medieval warfare and strategy.

Revision record

Iron Standard Update 2 — 7 September 2026. Rebuilt the campaign around the central contradiction between English battlefield victories and eventual territorial defeat; separated military success from occupation and state capacity; added explicit confidence grading, source genealogy, competing explanations and falsifiability; challenged longbow, Joan of Arc and artillery single-cause narratives; updated links to the new Crécy and Agincourt investigations while preserving the existing URL.

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