The situation of France was more than ever deplorable. The Armagnacs and the Burgundians were contending with each other for the power, and a third competitor had entered the lists; the dauphin, Louis, the eldest son of the unhappy Charles VI., arrived at manhood, and supported by his uncle, the Duke of Berry, endeavored to seize the reins of government. Dissolute and unmannerly, as profligate and as cruel as his adversaries, he sometimes made use of the king's name, at others he declared him incapable of directing his affairs, and plotted to drive out the Armagnacs or the Burgundians. Blood flowed in all parts, and the unhappy populations of the towns and the country, exhausted by taxes and exactions, sighed after each abuse for a new master: "What worse could the English do than that from which we suffer?"

While the French nation, overwhelmed by its misfortunes, lost even the wish of defending itself against foreigners, King Henry had summoned a council of the Lords at Westminster. In the last Parliament, his uncle, Beaufort, Bishop of Winchester and Chancellor of England, had delivered a great speech upon this text: "While we have time, let us do every good work." The king announced to his councillors that he had resolved to put his hand to the task and to recover his inheritance. All the prelates and barons approved of his intentions, and his brother John, duke of Bedford, was nominated Regent of England during his absence. The conditions of military service were determined. The king undertook to make a regular payment, curiously graduated according to the rank of those who followed him; a duke was to receive every day thirteen shillings and fourpence; an earl, six shillings and eightpence; a baron, four shillings; a knight, two shillings, an esquire, one shilling, and an archer sixpence. All were to bring a certain number of horses, which the king undertook to equip. Henry had pawned his jewels, contracted loans, and had collected a very considerable sum of money, when he marched forth in the month of July, to embark at Southampton.

At Winchester, the king encountered the Archbishop of Bourges, sent by the Duke of Berry, in the frivolous hope of appeasing the storm which threatened France. "I have a right to the crown," said Henry, "and I will conquer it with my sword." In vain did the archbishop invoke the help of God, of the Virgin Mary, and of the saints, who would defend the just cause of King Charles; in vain, exasperated by the disdain of the English, did he exclaim that the king had only made such liberal offers for love of peace, and that King Henry would soon find himself repulsed as far as the sea, if he should not be killed or made a prisoner; Henry contented himself with smiling. "We shall see shortly," said he; and loading the prelate and his retinue with presents, he sent him back with no other reply.

The embarkation of the troops had already commenced, when the king was suddenly warned of a plot against his life. One of his friends, Lord Scroop of Masham, in whom the king reposed such confidence, that he always made him sleep in his own chamber, and Sir Thomas Grey Heton, had conspired with the Earl of Cambridge, the brother of the Duke of York, and as treacherous as he. The king dead, the young Earl of March was to replace him upon the throne. The three conspirators suffered the penalty of their crime. Henry at length set sail for France, on the 13th of August, 1415. The fleet entered the Seine on the morning of the 14th, and thirty thousand men, which it carried, landed within a league of Harfleur. The spot was ill-chosen for the landing, and the defence would have been easy; but no obstacle presented itself to impede the operations of the English, and, on the 17th, King Henry laid siege to Harfleur. The town was strong and well defended by the Sire d'Estouteville; sickness was beginning to ravage the English army; several barons of consequence died, as well as a large number of soldiers; but the besieged suffered also, and the governor in vain asked for assistance.

The Sire d'Estouteville formed his resolution; he issued secretly out of the town and repaired in person to Rouen, where the French forces were beginning to assemble. But confusion and disorder reigned there; no one thought of delivering Harfleur. The brave governor returned, re-entered the town, and surrendered it on the 22nd of September, after a siege which had lasted thirty-six days. King Henry installed a garrison there, then embarked his sick and wounded soldiers, whom he sent back to England, and took account of his army thus diminished, nine thousand men at the utmost remained under his banners. His supporters hesitated to advance into France. Henry had sent to the dauphin a challenge to single combat; but Louis had not even replied.

The king silenced the timid counsels. "No," said he, "with the help of God, we must first see a little more of this good soil of France, which all belongs to us. We will go, with God's help, without hurt or danger: but if we should be interfered with, we will fight, and the victory will be ours." Reassuring his men thus, the King of England set out on his way to Calais, on the 6th of October. The army at Rouen, under the orders of the king and the dauphin, did not stir; but that of the Constable had preceded the English in Picardy, and every day troops passed by on their way to join him. Watched by some detachments larger than his entire army, Henry traversed Normandy without any obstacle; near Dieppe, however, he was attacked by the garrison of Eu, but the enemy was thrown back in disorder. Like Edward III., Henry found himself stopped by the river Somme, and could not discover a ford; Blanche Tache was guarded; the greater number of the passages were furnished with stakes. The soldiers were beginning to murmur, when, on the 19th of October, a passage was found between Bethencourt and Vogenme, and the English army crossed the Somme without impediment. The Constable had established himself at Abbeville, and the military council assembled at Rouen decided that battle should be given. The immense superiority of the French army had caused the wise usages of King Charles V. to be forgotten.

On the 20th of October, three French heralds presented themselves at the camp of the enemy, and the Duke of York conducted them to the king. "Sire," they said, bending the knee before him, "my masters, the Dukes of Orleans and Bourbon, and my lord the Constable, inform you that they intend to give battle to you." "God's will be done," replied the king without emotion. "And by which road do you intend to proceed?" resumed the heralds, who had noticed with amazement the small number of English tents, and the weary appearance of the soldiers. "That of Calais, straight along," replied Henry. "If my enemies wish to stop me, it will be at their peril. I do not seek them, but I will proceed neither faster nor more slowly to avoid them." And raising his camp on the morrow, Henry indeed continued his march, as though death or defeat could not lie hidden behind each hill, or await him in the neighboring plains. On the 24th he had crossed the river of Ternois, when he perceived the first columns of the enemy. He immediately formed his troops into battle order; but the Constable having fallen back upon Agincourt, the King of England took up his quarters in the village of Maisoncelles. The royal standard of France was planted on the road to Calais; death or victory was imperative.