The Lancastrian Phase of the Hundred Years' War (1415

The Lancastrian phase of the Hundred Years’ War, named for the English royal House of Lancaster, was the third and final phase of the conflict. It opened in August 1415 with Henry V’s invasion of France and ended with the French victory at the Battle of Castillon on 17 July 1453, followed by the surrender of Bordeaux on 19 October 1453. The phase encompassed some of the most dramatic events in medieval European history: the legendary Battle of Agincourt (25 October 1415), the methodical English conquest of Normandy 1417–1419, the Treaty of Troyes (21 May 1420), the death of Henry V at Vincennes (31 August 1422) and of Charles VI seven weeks later, the intervention of Joan of Arc in 1429, the trial and execution of Joan in 1431, the Congress of Arras in 1435, the French reconquest of Normandy (1449) and Gascony (1451–1453), and the final English defeat at Castillon.

The standard treatment is Sumption’s The Hundred Years’ War, vol. III (2009) and vol. IV (2015). The most useful French account is Contamine’s La Guerre de Cent Ans (1968). The most useful treatment of the war’s political dimension is the work of the contributors to the Oxford Handbook of the Wars of the Roses (2015, ed. Doran).

The opening of the war

The Lancastrian phase opened after a quarter-century of uneasy peace, broken only by minor incidents and the long-running French civil war between the Armagnacs and the Burgundians. The English kings of the late 14th and early 15th centuries, beginning with Henry IV and continuing with his son Henry V, were kings of England by virtue of usurpation, and they needed a foreign war to legitimise their dynasty and to satisfy the war-hungry English aristocracy.

The French, meanwhile, were in a state of political collapse. King Charles VI was intermittently insane, and the royal government was split between the Armagnac and Burgundian factions. The assassination of Louis, Duke of Orléans, in 1407, on the orders of John the Fearless, Duke of Burgundy, had led to a long and bloody civil war that had, by 1415, exhausted both sides. The French were unable to mount an effective opposition to a determined English invasion.

Henry V reopened the war in August 1415, ostensibly to enforce his family’s ancient claim to the French throne. At the head of a small but well-equipped English army, he crossed to France and won the most famous English victory of the entire conflict.

Agincourt and the conquest of Normandy, 1415–1419

The Battle of Agincourt, fought on 25 October 1415 in the narrow plain of Picardy, was the first great engagement of the phase. The English, perhaps 6,000 strong, destroyed a French force two to four times their size. The English dead were perhaps 400–600; the French dead, 1,500–4,000 of all ranks, were heavily concentrated in the upper nobility. The Duke of Alençon, the Duke of Brabant, the Count of Nevers, the Constable d’Albret, and a substantial proportion of the French chivalric class were killed. The battle is treated in detail in its own cluster article; the standard modern treatment is Curry’s Agincourt: A New History (2005) and The Battle of Agincourt: An Anatomy (2020).

The English followed up Agincourt with a methodical conquest of Normandy. The campaign, conducted by Henry V and his brother Thomas, Duke of Clarence, was marked by a series of sieges: Harfleur (1415), Caen (1417), Cherbourg (1417), Rouen (1419), and a string of smaller places. The Norman nobility, divided by the civil war and weakened by the loss of their leaders at Agincourt, were unable to mount an effective resistance. By 1419 Henry controlled most of Normandy and was in a position to dictate terms to the French.

The Treaty of Troyes, 21 May 1420

The Treaty of Troyes, signed on 21 May 1420, was the most ambitious diplomatic instrument of the war. The mad King Charles VI, under the influence of Queen Isabeau and the Burgundian faction, recognised Henry as regent and heir of France, and contracted Henry to marry Catherine of Valois. The Dauphin, the future Charles VII, was disinherited. The treaty was the culmination of Henry’s strategic triumph, and it seemed to settle the fate of France in favour of the English.

The treaty depended on the survival of the two principals. Henry died of dysentery at the Château de Vincennes on 31 August 1422, seven weeks before Charles VI (who died on 21 October 1422). The infant Henry VI was proclaimed King of England and France, but the Dauphin refused the disinheritance and held the centre and south.

The minority of Henry VI

The death of Henry V left the English cause in the hands of an infant. Henry VI, the son of Henry V and Catherine of Valois, was less than a year old when he became King of England; the regency was exercised by his uncles, John, Duke of Bedford, and Humphrey, Duke of Gloucester. Henry was also proclaimed King of France, but the reality of English power north of the Loire was much less impressive than the title suggested.

The English won an important victory at the Battle of Verneuil (17 August 1424), in which a Franco-Scottish army under the Earl of Douglas and the Duke of Alençon was destroyed, with the Scottish contingent almost annihilated. But the death of the Earl of Salisbury at the siege of Orléans in November 1428 marked the beginning of a long period of English decline.

Joan of Arc and the Loire campaign, 1429

The arrival of Joan of Arc at the Dauphin’s court at Chinon in early March 1429, the lifting of the siege of Orléans on 8 May 1429, the French victories on the Loire in June, and the coronation of Charles VII at Reims on 17 July 1429 transformed the strategic situation. The English position in France, which had seemed so strong a few years earlier, began to crumble.

The standard treatment of Joan’s career is the Procès de Jeanne d’Arc (the trial and rehabilitation transcripts). Joan’s capture at Compiègne on 23 May 1430, her sale to the English, and her execution at Rouen on 30 May 1431 were propaganda disasters for the English, but did not stop the French recovery. The duchy of Burgundy, the key English ally, was eventually detached from the English cause at the Congress of Arras in 1435.

The reconquest of France, 1435–1453

The Congress of Arras in September 1435 ended the war between France and Burgundy. Philip the Good, Duke of Burgundy, abandoned the English alliance; in exchange, Charles VII recognised Burgundian sovereignty over a number of territorial concessions. The French then turned their attention to Normandy, which they reconquered in 1449, and to Gascony, which they recovered in 1451. The English, weakened by the loss of their continental allies and by the political troubles of Henry VI’s minority and later reign, were unable to mount an effective resistance.

The final English army in France was destroyed at Castillon on 17 July 1453, and the last English city, Bordeaux, surrendered on 19 October 1453. The Plantagenet dream of a continental monarchy was over. The English crown, weakened by the loss of the war, by the financial exhaustion of Henry VI’s government, and by the king’s first major bout of mental illness in 1453, was in no position to reopen the conflict.

The significance

The Lancastrian phase of the war is the most famous and the most mythologised. The Battle of Agincourt became the model of English military prowess, and the figure of Henry V became the model of the medieval warrior-king. The trial and martyrdom of Joan of Arc became one of the most powerful stories in the French national tradition. The final English defeat at Castillon marked the end of a long era and the beginning of a new one.

The phase also produced, in the long run, three of the most important institutions of the French state. The permanent taille (granted by the Estates of Orléans in 1439), the compagnies d’ordonnance (1445), and the standing artillery train under the Bureau brothers were the bones of the absolute monarchy that Louis XIV would inherit. The phase also produced, in England, the political crisis that would lead directly to the Wars of the Roses. The incapacity of Henry VI, the loss of Normandy and Gascony, the financial exhaustion of the crown, and the dynastic challenge of the Duke of York are all direct consequences of the Lancastrian war.