2015 witnessed the 600th anniversary of one of England’s most celebrated military victories, John Goodall explains the context of the battle and its importance

This illustration (above) of about 1450 of the Battle of Agincourt comes from an English chronicle known as the Brut. The importance of the archers in the battle is given particular emphasis in its account. Even so, no medieval description represents Agincourt as a victory won by the lowly bow.

On August 13, 1415, an English army disembarked on the coast of Normandy. It was personally led by Henry V, who came with the avowed intent of asserting by force of arms his title to the throne of France. This claim, inherited from Edward III, was the cause of intermittent fighting between the two kingdoms between 1337 and 1453, a conflict familiar today as the Hundred Years’ War. Henry V was not only driven by the prospect of conquest, but by an urgent need to establish his own authority at home. Crowned in 1413, he was the son of Henry IV, a usurper to the throne. The tenuous character of his regime was illustrated just before his departure with the exposure of the ‘Southampton Plot’ to depose him by a circle of noblemen.

With parliamentary support, Henry stretched his resources to the utmost for the campaign and marshalled an army of about 12,000 men prepared for 12 months’ service. This had been raised in conventional form, with captains entering into contracts to provide specified numbers of men. Forming the backbone of the army were men at arms, often described as ‘esquires’ in reflection of their social status. The members of this heavily armoured force included those of gentle and noble birth and they were paid according to their degree. English men at arms characteristically rode to battle, but deployed on foot in the field.

Far more numerous were bowmen, some constituted as discrete companies and others attached to individual retinues, including men at arms. Since the early 14th century, all adults in England had been obliged by law to practice archery using the longbow. Drawn from these, the skilled mercenaries deployed in the battle were lightly armoured so that they could draw their bows quickly and easily. Surviving documentation suggests that they constituted the bulk of the army by a ratio to men at arms of 4:1— roughly 9,600 bowmen to 2,400 men at arms—a higher proportion than was probably considered desirable. Nevertheless, far less well paid than the men at arms, they were a cheap way of enlarging the army.

Upon landing, Henry V invested Harfleur. Set at the mouth of the Seine, the city controlled access to Rouen, the capital of Normandy, the ancient possession of England’s kings and lost to their control since 1204. Harfleur put up stiff resistance and when it fell, five weeks later, on September 22, it was too late in the season for much effective further campaigning. The English army, moreover, was depleted by about a quarter from the combined effects of casualties, disease and the needs of furnishing a new garrison for the city. Rather than withdraw directly, however, Henry decided to march the remains of his army to the English-held city of Calais. His intention was to mount a destructive raid or chevauche along the route. The march should have taken about eight days. The French had mustered forces of their own immediately after the invasion. They never attempted the relief of Harfleur, however, nor did they consolidate in one place. Instead, they shadowed Henry V’s chevauche as soon as it began and blocked a crucial crossing of the River Somme at Blanchetaque.

With the direct route to Calais closed, the English were forced to march inland along the river and their road became progressively longer. Food was already running short when Henry V exploited a wide bend in the river to steal a march on his opponents and cross to the north bank. There were skirmishes during this long march through north-eastern France and it was from captured prisoners that Henry V learnt of a plan to destroy his archers in battle using cavalry (astonishingly, a French battle plan confirming this intention survives). In response, he issued an order on October 17 that each man was to cut a 6ft stake sharpened at both ends.

Three days later, on October 20, the French sent a formal summons to battle near Azincourt. It’s not understood what dictated the site of the battle and some doubt has been cast recently on its exact location. As it appeared in 1415, however, the field was narrow and defined on either side by forest.

It can be inferred from surviving— but often contradictory—accounts that Henry V drew up his men at arms in a line comprising three divisions or battles with massed archers to each side. The archers ranged forward from the line and drove stakes into the ground as a protection against cavalry. There may also have been archers in the centre of the position or ranged in front of it and one source speaks of 200 archers being hidden in a wood to ambush the French. The baggage train was used to defend the rear of the position. There is a description of the English kneeling before the battle and each man tasting the earth as a reminder of his mortality.

The French army was comprised, like its English counterpart, of men at arms and archers and crossbowmen. Estimates of its size vary widely. Most sources agree that it was larger than the English army, but this may simply reflect the fact that it had many more men at arms. Whatever the case, comparison with other armies of the period and the absence of the King effectively preclude it from exceeding 15,000 men. Thus the traditional view of a tiny English army facing a vast French one certainly needs modification. The plan was to launch a simultaneous attack on the English army with cavalry riding down the archers on each flank and a huge battle of about 6,000 men at arms on foot overwhelming its centre. French accounts—admittedly coloured by the catastrophic outcome of the battle— suggest that their army was overconfident and mismanaged. Apparently, no one wanted to attack the archers when the glory and riches of the field were promised in the centre. As a result, the numbers of cavalry sent to attack the English archers were hopelessly inadequate. To make matters worse, in their eagerness for the fray, the French men at arms pushed in front of the supporting crossbowmen and archers, obscuring their targets.

However eager for the fray they were, however, the French did not immediately attack. Instead, after a wait, Henry V was compelled to provoke them. He ordered his line forward to extreme arrow range. With their stakes driven in once more, his archers fired and the battle began. The inadequate French cavalry attack was defeated and the survivors returned across the field, where they disrupted the advance of the main battle. This huge body of men was pressed together by the rain of arrows from either side. Underfoot, the ground, soaked by recent rain, became a quagmire. When the French force closed with the English, therefore, its men at arms were exhausted and unable to fight.

Now, the English archers saw a new opportunity. With their arrows exhausted, they joined in the fray, using mallets, knives and even wooden stakes to attack the heavily armoured men at arms. The battle became a massacre, with men killed or suffocated to death in the mud. Many prisoners were taken and the English won the field. There followed two celebrated episodes that have no direct bearing on the main narrative of the battle.

The first was an attack on the English baggage train and the second Henry V’s notorious order to kill the French prisoners. The latter is probably to be explained by an apparent—or imagined— rallying of the French. This additional blood-letting made little impression on contemporaries, but has been much condemned by posterity.

It’s quite clear that the English victory was unexpected and complete. All accounts of the battle emphasise the high casualties suffered by the French. On his return home, Henry made the most of both Agincourt and the campaign, yet he gained little tangible advantage from either: he neither won land nor forced the French to the negotiating table. This was more properly a moral victory that bolstered his right to the throne. It also aggravated the internal collapse of the French realm.

It was this latter result that really brought him—through the Treaty of Troyes in 1420—his ultimate desire: the promise of the French Crown. As a prospective French king, however, Agincourt ceased to be something to boast about. As a final irony, Henry’s early death robbed him of his prize