The siege and relief of Cosne, May–August 1422
With the tide turning strongly in his favour, Henry V might have been expected to lose interest in a negotiated settlement with the Dauphin. In fact, the summer of 1422 was a time of intense diplomatic activity. Bishop Albergati arrived in France in the middle of May and joined forces with the peacemakers of the Duke of Savoy. In the course of June and July, he covered several hundred miles and met all three principals. Albergati was a discreet man and his reports to the Pope have not survived. We therefore know very little about these exchanges. The Duke of Savoy later complained that Henry been uncooperative. But in fact the King seems to have got on well with the legate. He liked the company of scholars and holy men and was a great patron of the Carthusians. According to the Florentine scholar Poggio Bracciolini, then living in London in the household of Bishop Beaufort, the two men struck up an immediate rapport. For his part the nuncio reported that Henry was genuinely anxious for peace. How realistic these hopes were is hard to say. It is unlikely that any terms acceptable to Henry V would ever have been agreed by the Dauphin, and there was the Duke of Burgundy to satisfy as well. Albergati seems to have been taken aback by the ferocity of the hatreds dividing the two French camps. His mission was probably doomed before it began, even had Henry V lived.
In fact, he was already ill when he met the nuncio and, although neither of them knew it, he had little time left. The summer of 1422 was extremely hot. The court had fled from Paris, which was in the grip of another epidemic of smallpox. At the end of June Henry experienced the symptoms of dysentery. On 7 July he was moved to Vincennes. The news of his condition quickly got out. Processions were organised for his recovery in the streets of Paris. A specialist was summoned from England.
Henry’s last illness coincided with a severe military crisis. At the end of May 1422, Tanneguy du Châtel had mustered a large army at Beaugency on the Loire and invaded Philip of Burgundy’s county of Nevers, which served as the western bastion of the duchy of Burgundy. The Dauphinist forces comprised about 2,000 French troops and what remained of the army of Scotland, probably between 3,000 and 4,000 men altogether. The Scots had not been paid for some time, and in order to mobilise them Tanneguy was obliged to settle their arrears, 5,415 gold écus in undepreciated coin, out of his own pocket. The Dauphinists’ campaign plans had been in the making for several weeks, and some inkling of them had reached Paris and Dijon. The Burgundian Marshal of France, Antoine de Vergy, had visited the region in the spring to organise its defence. Nevertheless, the offensive caught the government off guard when it came. Tanneguy swept through the Nivernais occupying all the principal castles on his route and encountering no serious opposition. In the third week of June, he laid siege to La Charité, a walled town on the right bank of the Loire which was the site of a famous Benedictine abbey and an important stone bridge over the river. There, he joined forces with the Vicomte of Narbonne, who had come up from Languedoc with another army. Fresh companies were reported to be on their way from Italy and Castile to reinforce them. In spite of its importance, there appears to have been no garrison at La Charité. Negotiations were in hand with the inhabitants to station troops in the town, but nothing had come of them by the time the Dauphinist armies arrived.
The Duke of Burgundy was at Troyes when the news of Tanneguy du Châtel’s offensive reached him. He had planned to march north to join Henry V in a joint campaign against the last remaining Dauphinist garrisons of the north, and he was occupied with the muster of his retainers in Burgundy and Champagne. The threat to La Charité forced an abrupt change of plan. The Duke returned at once with his army to Dijon. There, he ordered the recruitment of more troops throughout his domains and sent urgent appeals for help to Henry V and the Dukes of Savoy and Lorraine. Some 250 men-at-arms were detached from his army at once and sent to defend La Charité. They were too late. On 25 June, the day after the Duke reached Dijon, the town opened its gates to the Dauphinists and the vital bridge over the Loire fell into their hands. Leaving a garrison to hold it, Tanneguy and the Vicomte of Narbonne marched down the Loire and besieged the other major bridge-town of the region fifteen miles away at Cosne. There was a garrison at Cosne. But it was in no position to withstand a long siege. The captain of the town sent a runner to Philip of Burgundy to warn him that he could not hold out for long. Philip replied that help was on its way. But within a few days the garrison was forced to enter into a conditional surrender agreement. A date, 12 August, was fixed for its surrender unless a relief force had reached the town by then, under the command of the Duke of Burgundy in person.
Henry V, sick as he was, seized upon the chance of a pitched battle with the Dauphin’s forces outside Cosne. It offered him the trial by battle that he had been looking for ever since the Dauphin had emerged as his principal opponent in 1419. He agreed with Philip of Burgundy that the challenge should be accepted. The Duke’s heralds were sent to agree with the Dauphin’s on a site for an arranged battle on the right bank of the Loire near Cosne. Meanwhile, the English and Burgundians bent all their efforts to assembling a large enough army in the short time available. The Earl of Warwick abandoned the siege of Le Crotoy which he had only just begun. A screen of troops under Ralph Butler was left to cover Saint-Valéry until the day appointed for its surrender. John of Luxembourg rose from his sickbed in Paris to find troops in Picardy. Hughes de Lannoy raised companies among the nobility of Flanders. All of these contingents reached Paris in the second half of July. The remaining companies, from the Duke’s eastern domains, mustered at the same time in the plain south of Châtillonsur-Seine. The most reliable contemporary estimate puts the strength of the combined force at 12,000 men, of whom about 9,000 were provided by the allies and subjects of the Duke of Burgundy and about 3,000 were English. It was agreed that the entire army would assemble at Auxerre and march together to Cosne. At Vincennes Henry V, racked by fever and gastroenteritis and unable to keep down the medicines that his doctors prescribed for him, refused to submit to his illness. When the army left Paris in the third week of July 1422, he dragged himself from his bed and had himself carried at its head in a litter. It took his cortège several days to reach Corbeil, and by the time it got there, it was obvious that the King could go no further. He summoned his brother the Duke of Bedford and his uncle the Duke of Exeter and ordered them to take over the command. They marched on without him. In Paris, there were daily processions for his recovery, while across all France prayers and masses were said for the fortunes of each side in the battle to come.
The two allied armies met at Vézelay, south of Auxerre, on 4 August 1422, and reached Cosne six days later on the 10th. There, they found that the besiegers had vanished. The siege lines were empty. There was no sign of the Dauphin or his army. On 12 August, the day appointed for the battle, Philip of Burgundy, the Duke of Bedford and John of Luxembourg drew up their army in battle array at the agreed site. They stood in line all day before returning to their encampments in the evening light. No one appeared to fight them. Eight miles away, on the opposite side of the river, the Earl of Buchan was encamped outside the town of Sancerre with part of the Dauphin’s army. Buchan made no attempt to challenge the Anglo-Burgundian force. His sole object was to stop the Anglo-Burgundians crossing into Berry. Small forces had been stationed along the left bank to watch the movements of the English and Burgundians and block the passage of the bridges and fords. On 13 August, John of Luxembourg took part of the Anglo-Burgundian army and raided towards La Charité hoping to find an undefended crossing, but the Dauphinists followed him from the opposite bank until he gave up and returned to Cosne. That evening the Duke of Burgundy and the Duke of Bedford marched away with their men.
The Dauphin’s commanders had given up all thought of fighting a pitched battle at least two weeks before, when they became aware of the scale of the other side’s preparations. The exact strength of their own army is not known, but it was certainly much smaller than their enemy’s. The Anglo-Burgundians claimed the moral high ground, and perhaps they were entitled to it. But the strategic gains were all on the Dauphin’s side. His captains had not gained Cosne. The town received a Burgundian garrison and the hostages which it had given for its surrender were returned. But he had achieved his objectives. La Charité, a major bridgehead into Burgundian territory, remained in his hands, and the plans of Henry and Philip of Burgundy for a summer campaign in the north had been spiked. The Earl of Warwick had been forced to lift the siege of Le Crotoy, and a vital respite had been given to the Dauphin’s last surviving garrison on the Oise, at Guise.
Towards the end of July 1422, after Buchan and Tanneguy du Châtel had decided not to fight at Cosne, they sent the Vicomte of Narbonne with part of the army west to join the Count of Aumale on the march of Maine. They expected to find Lower Normandy denuded of troops to fill the ranks of the Anglo-Burgundian army. They were not disappointed. Not only were all the principal English captains and many of the garrison troops with Bedford in the Nivernais, but a large number of men had just been withdrawn from the garrisons of Lower Normandy and ordered north to be present at the surrender of Saint-Valéry, which was due to open its gates on 4 September. As a result, Aumale and Narbonne were able to do considerable damage with very little opposition. They marched deep into Normandy, penetrating within forty miles of Rouen. Bernay, an unwalled town with no garrison, was sacked. The English commander in the sector, Thomas Lord Scales, came up with a field force of a few hundred men, but they were outnumbered and driven off with heavy losses. As the Dauphinists turned for home, another local captain, Sir Philip Branch, collected a field force from the residues of nearby garrisons, and valiantly tried to block the invaders’ retreat at Mortagne in Perche. On 14 August his men, dismounted in carefully prepared positions and protected by a line of stakes, determined to take on a far stronger enemy. But the odds were too great. They were scattered by a single cavalry charge. Many of them were killed or captured in the pursuit.
The strategic impact of this raid was small, but magnified by report. The Dauphinists claimed an impossibly high tally of casualties. The Italian news network even reported that the Vicomte of Narbonne’s army had entered Paris. For the English it illustrated once more the abiding problems of military occupation. They were everywhere overstretched. Unable to come to grips with their enemy on their own terms, they were compelled to fight an expensive war of static defence in Normandy and debilitating sieges everywhere else. In order to take possession of Saint-Valéry and contribute some 3,000 men to the army of Cosne they had had to reduce their strength in Normandy below the minimum level consistent with effective defence. Even companies that were never involved in a fight were losing men all the time to sickness and desertion. In the four months since the Duke of Bedford had last landed in France, his company had lost nearly a quarter of its strength. For the moment, losses like these were being made good with fresh drafts from England. But for how much longer?