The Battle of Agincourt (1415): Henry V's Greatest Victory

The Battle of Agincourt, fought on 25 October 1415 in the narrow plain of Picardy, is the most studied single day of the Hundred Years’ War and the engagement that did most to fix the popular image of medieval English arms. Henry V’s army of perhaps 6,000 men, returning from the conquest of Harfleur and marching overland toward Calais, destroyed a French force two to four times its size, and within hours the military leadership of France had been decimated. The dead included the Constable Charles d’Albret, the Dukes of Alençon and Brabant, the Count of Nevers, the Counts of Marle, Vaudemont, and Roucy, and a substantial proportion of the higher French nobility. Modern estimates cluster English losses at 400–600 and French losses at 1,500–4,000 of all ranks; the older figures of 6,000–10,000 French dead are not credible.

Anne Curry’s Agincourt: A New History (2005) and her later The Battle of Agincourt: An Anatomy (2020) are the standard modern treatments, both written to correct the long-standing Shakespearean image. Jonathan Sumption’s account in The Hundred Years’ War, vol. III (2009), is briefer but more strategically framed.

The campaign of 1415

Henry V crossed to France in August 1415 with about 12,000 men, the largest English army sent abroad since Crécy. The objective was the conquest of Harfleur, the port at the mouth of the Seine whose possession would give England a permanent base of operations in Normandy. The siege lasted five weeks rather than the days Henry had hoped, dysentery ravaged the army, and the king was forced to abandon a quarter of his force at Harfleur before beginning the march north. By the time the English reached the ford of the Somme in mid-October they were some 6,000 effectives, sick, hungry, and encumbered with the sick and wounded.

The French, under the constable Charles d’Albret, had assembled a large force on the line of the Somme and shadowed the English march. They intended to bring the English to battle on ground of their choosing, with a front wide enough to envelop them. Henry’s choices were to fight, starve, or surrender. He chose to fight.

The battlefield

The two armies came into contact on the evening of 24 October near the village of Agincourt, between two woods that constricted the available frontage to perhaps 1,500 yards. Henry deployed his army in the conventional English formation: a central line of dismounted men-at-arms flanked by wedges of longbowmen driven into the ground with sharpened stakes. The vanguard he led himself; the rearguard was under the Duke of York. The site has been the subject of extensive modern survey work, summarised by Curry (2005, 2020), and the modern consensus places the English line on a slight forward slope between the woods of Tramecourt and Agincourt, with the approach funnelled by a fresh-ploughed field on the English right.

The night of 24–25 October was wet, and the morning of the battle was clear. The French spent the hours before the engagement arguing about who would have the honour of the vanguard; the English spent them hearing mass and receiving communion.

The battle

The French attacked in the late morning. Their plan was for the mounted men-at-arms to ride down the English archers before they could loose, supported by a body of dismounted men-at-arms following behind. The crossbowmen, deployed forward, were broken by longbow fire almost immediately; the cavalry, advancing through mud and into arrows, never closed with the English line. As the first wave recoiled into the second, the French lost all order.

The English counter-attack in the early afternoon, by the dismounted men-at-arms, completed the rout. According to the most credible chronicle accounts, the longbowmen then ran forward to despatch the fallen. Henry’s order during the battle, that the baggage train and the non-combatants were to be slaughtered after a French attack on the rear, has been the subject of vigorous historical debate since the nineteenth century: the Gesta Henrici Quinti records the order, the Chronique de Normandie does not, and the standard reading is that some hundreds of prisoners were killed before the order was countermanded.

The dead

The names recorded in the French obituaries and in the Bedford Roll are what made Agincourt a political disaster as well as a military one. The Duke of Alençon, who according to some accounts reached Henry and struck off a piece of his crown, was killed and his body recovered. The Duke of Brabant (Anthony of Burgundy) was killed; the Count of Nevers, also Anthony of Burgundy in some accounts and a separate figure in others, died of his wounds. The Constable d’Albret, the Counts of Marle, Vaudemont, Roucy, and Dampierre, and the Admiral of France were among the dead. The English peerage lost the Duke of York and the Earl of Suffolk.

The French dead were heavily concentrated in the upper nobility, and the demographic and political consequences were severe: a generation of French military leadership had been removed in a single morning. The disaster, as Georges Duby argued in Le Dimanche de Bouvines (1973), is comparable in its political effect to the French disaster at Bouvines in 1214.

Why the French lost

The French defeat had three structural causes and a series of immediate ones. The structural causes were the longbow (a weapon the French could match in volume only by recruiting Genoese crossbowmen, who were slower and had shorter range), the absence of a French tactical doctrine for using it, and the political pressure on the constable to give battle. The immediate causes were the constricted battlefield, the muddy ground, the late hour of the attack, the failure of the cavalry to coordinate with the dismounted men-at-arms, and the disastrous collision of the first and second French lines.

The most useful single treatment of the tactical question is Curry’s Anatomy (2020), which subjects every element of the traditional account to forensic re-examination. The older view, set out in the Gesta Henrici Quinti and followed by generations of English historians, that the longbow alone won the battle, has been qualified: the mud, the constricted front, and Henry’s tactical handling of the engagement were equally decisive.

The legend of Agincourt

Shakespeare’s Henry V (1599), working from Holinshed and Hall, fixed the image: the St. Crispin’s Day speech, the king disguised among his men on the eve of battle, the French dead piled in carts. The historical Henry V was a serious, calculating ruler rather than Shakespeare’s idealised monarch, and the tactical reality of the battle was messier than the play suggests. But Shakespeare’s version is the version the world remembers, and the English memory of the war has been shaped by it more than by any other work.

The French memory has been shaped by the opposite image: the destruction of the chivalric class, the decades of recovery that followed, and the long patient work of reconquest from 1429 to 1453. The battle is conventionally treated, in French historiography, as the moment when the English longbow reached the limit of its strategic potential: no English army ever won a comparable victory again.

Agincourt is one of the canonical examples of the medieval “military revolution” in the sense developed by Clifford Rogers in War Cruel and Sharp (2014) and by the contributors to his Oxford Encyclopedia of Medieval Warfare and Military Technology (2010). The strategic consequences of the engagement are treated in the Lancastrian phase and the Battle of Castillon articles.