Campaign and battle
On 11 August 1415 Henry sailed from Southampton with an army of about 12,000 men. They reached the northern French coast three days later, and started their campaign by surrounding the port of Harfleur. This siege lasted until 22 September, and cost more in money and casualties than anticipated – read more about it on our blog.
Henry marched east on 5 October with an army of about 9,000 men, attempting to reach English-controlled Calais. French forces followed them, trying to block the route northeast and force a battle. After evading the French and crossing the River Somme on 19 October, the English army was finally confronted about 45 miles south of Calais, near the village of Azincourt.
On 25 October, Henry led the English army into the battle of Agincourt. A larger French force was led by the Marshal of France, Boucicaut, and the Constable of France, Charles D’Albret. The English were deployed in three battles (groups) of men-at-arms, most likely arranged in a line side by side, with divisions of archers positioned either at the sides or between each battle. The French army was also divided into three battles, but deployed with a vanguard in front, the main battle in the middle and a rearward battle at the back.
A combination of factors contributed to the English victory. Henry was a clear and decisive leader; in contrast, the French army’s chain of command was muddled, which caused a lack of coordination.
The terrain also suited the English forces. The field narrowed in width between the French and English positions, which undermined French superiority of numbers. Woodland on either side provided protection from flanking attacks by French cavalry. Further anti-cavalry measures, like the use of sharpened stakes, were taken by English archers to protect their position.
Archers played a crucial role, with contemporary chroniclers remarking on their impact. Heavy armour worn by many French men-at-arms offered moderate protection, but their less well armoured horses were vulnerable to arrows.
Finally, wet weather the day before the battle made the ground muddy and dangerous. Many of the French men-at-arms fell as they advanced on foot, pressed forward by eager soldiers behind them. Fallen, they were vulnerable to an English sword and arrow – or to drowning in the mud.