Siege of Romorantin

Since the Norman Conquest of 1066, English monarchs had held titles and lands within France, the possession of which made them vassals of the kings of France.^[1] Following a series of disagreements between Philip VI of France (r. 1328–1350) and Edward III of England (r. 1327–1377), on 24 May 1337 Philip's Great Council in Paris agreed that the lands held by Edward III in France should be taken back into Philip's hands on the grounds that Edward III was in breach of his obligations as a vassal. This marked the start of the Hundred Years' War, which was to last 116 years.^[2]

Edward's eldest son, Edward of Woodstock, later commonly known as the Black Prince, was given command in Gascon in 1355^[3][4] and arrived there on 20 September accompanied by 2,200 English soldiers.^[5][6] Gascon nobles reinforced him to a strength of somewhere between 5,000 and 6,000 and provided a bridging train^{[7][note 1]} and a substantial supply train.^[8] The Black Prince set out on 5 October on a chevauchée, which was a large-scale mounted raid. The Anglo-Gascon force marched from Bordeaux, the capital of Gascony, 300 miles (500 km) to Narbonne and back to Gascony, devastating a wide swathe of French territory and sacking many French towns on the way. The local French forces avoided battle and there was little fighting. The expedition returned to Gascony on 2 December having marched 675 miles (1,100 km).^[9] No territory had been captured, but enormous economic damage was done to France; the modern historian Clifford Rogers concluded "the importance of the economic attrition of the chevauchée can hardly be exaggerated."^[10]

The English component resumed the offensive after Christmas^[11] to great effect, with more than 50 French-held towns or fortifications captured during the following four months.^[12] Local French commanders attempted no countermeasures^[13][14] and several members of the local French nobility went over to the English.^[15] Money and enthusiasm for the war were running out in France. The modern historian Jonathan Sumption describes the French national administration as "fall[ing] apart in jealous acrimony and recrimination".^[16] A contemporary chronicler recorded "the King of France was severely hated in his own realm". Arras rebelled and killed loyalists. The major nobles of Normandy refused to pay taxes and on 5 April 1356 King John II of France, Philip's son and heir, arrested several of their leaders, executing four.^[17] Several Norman nobles turned to Edward for assistance.^[18]

The French announced an arrière-ban, a formal call to arms for all able-bodied males, on 14 May 1356. The response was unenthusiastic and the call was repeated in late May and again in early June. The French were so short of cash they were unable to pay wages to those men who did muster.^[19] The Black Prince received reinforcements of men,^[20] horses, food and materiel during the spring.^{[note 2][21]} Ralph, Earl of Stafford, arrived in mid-June with further reinforcements and supplies.^[22] The main French army was in Normandy where John committed it to a siege of Breteuil, the last rebel-held fortification holding out against him in eastern Normandy. Little progress was made, as Breteuil was well garrisoned and had food for a year. The French attempted to mine under the walls, to no avail.^[23]

The force which the Black Prince led north contained some 6,000 fighting men: 3,000 English and Gascon men-at-arms;^{[note 3]} 2,000 archers, almost entirely English and Welsh longbowmen; and 1,000 other infantry, predominately Gascons. They were accompanied by approximately 4,000 non-combatants.^[25][26] All the fighting men were mounted, including those who would only fight on foot, such as the archers.^[27]

The Anglo-Gascon army then separated into three divisions, known as battles, and marching abreast of each other began to systematically devastate the countryside. There would be approximately 40 miles (64 km) between the flanking units, enabling the army to devastate a band of French territory more than 50 miles (80 km) wide yet be able to unite to face an enemy at approximately a day's notice. They advanced slowly, to facilitate their tasks of looting and ruin.^[28][27] The modern historian David Green has described the progress of the Black Prince's army as "deliberately destructive, extremely brutal ... methodical and sophisticated."^[29] Several strong castles were assaulted and captured.^[30] Fortifications which were too strong to storm, or which repulsed the first attack, were bypassed – to avoid leaving parts of the Anglo-Gascon army behind. The populaces of most towns fled, or surrendered at the first sight of Anglo-Gascon troops. Overall, the French offered little resistance and there was no field army to prevent the Prince's forces from dispersing widely to maximise their effect on the French countryside.^{[31][32][33][34]}

The main French army remained in Normandy. Despite it being clear Breteuil could be neither stormed nor starved, John felt that capturing the place was a matter of honour. At some point in August the French pushed an unusually large belfry, or mobile siege tower, up to the walls of Breteuil and launched a large assault. The defenders set fire to the belfry and repulsed the attack. Eventually, around 20 August, John offered the garrison of Breteuil free passage to the Cotentin, a huge bribe, and permission to take their valuables and goods, which persuaded them to vacate the town. The French army promptly marched south, as all available forces were concentrated against the Black Prince.^[35]

The Anglo-Gascons were advancing in the general direction of Bourges, a large and well-fortified town where the Count of Poitiers had brought a small French army from Languedoc and was rallying additional forces. Poitiers retreated in front of the Anglo-Gascons; a division of the Anglo-Gascon army tried and failed to take the town, then burnt the suburbs and continued north. This division reached Aubigny, 30 miles (48 km) to the north, by 28 August,^[36] which was looted and razed. Anglo-Gascon forces probed to the north, searching for a place where their army could cross the Loire. But it had been a wet summer, causing the river to flow too fast and be too deep to be forded and the French had destroyed all bridges which they were not certain they could defend. The same day a large French scouting party was driven off near Aubigny with losses. Some distance to the south the central component of the Black Price's division passed through Châteauroux, where it was decided to press on after the more advance divisions rather than besiege the town's castle.^[32][37][34]