Siege of Hennebont (1342)

The Siege of Hennebont took place between late May and late June 1342 when the forces of Charles of Blois conducted an unsuccessful siege of the fortified port of Hennebont, commanded by Joanna of Montfort. The conflict was a part of the Breton Civil War, a dynastic dispute between two claimants to the Duchy of Brittany which had broken out the previous year. A complicating factor was the pre-existing Hundred Years' War between France and England. Philip VI of France was supporting Charles of Blois, his nephew; while Edward III of England had promised military assistance to Joanna, the wife of the rival claimant, John of Montfort. A truce between France and England was in place when the siege started but was due to expire in June 1342.
Charles's French army overran eastern Brittainy and captured John of Montfort. Joanna took up the cause and concentrated her resources in Hennebont. In late May 1342 Charles moved on the town. On arrival part of his army advanced against orders and attacked some of the town's defenders who were formed up outside its gate. More troops were pulled into this fight before the French were pushed back in a disorderly retreat. The Montfortists pursued, inflicting many casualties and burning the French camp. Two days later the French launched a series of better-planned assaults, but all were repulsed. The main French force moved on, leaving a detachment to try and starve the town into surrender. In late June this too left, after a small English force had reinforced the town from the sea. In July Charles was strongly reinforced and returned; the Montfortists abandoned Hennebont and redeployed further west, hoping for English reinforcements.
Brittany was a province of France. Although the dukes of Brittany were vassals of the French kings, they governed the duchy as all but independent rulers. Nevertheless, when the Hundred Years' War broke out in 1337 between France and England the Duke of Brittany, John III (r. 1312–1341), fought alongside his feudal lord the King of France, Philip VI (r. 1328–1350). John died on 30 April 1341, leaving a disputed succession: both his niece, Joan of Penthièvre, and his younger half-brother, John of Montfort, claimed the dukedom; Joan was married to Charles of Blois, a well-connected and militarily oriented French nobleman who was also a nephew of the King of France. John had the stronger legal claim but the aristocracy and clergy knew little about him and mostly preferred Charles' claim. What support John had came largely from the lower levels of society, especially in the towns.
Starting in early June 1341 John seized almost all of the fortified places in Brittany and by mid-August had all but made good his claim to the Duchy. Philip initially disregarded the situation but, correctly suspecting that John was negotiating with the English, had Charles declared the rightful heir on 7 September. The French King liked the idea of having a relative as the duke as it would bring the traditionally semi-autonomous province more firmly under royal control. He was willing to commit considerable military resources to achieve this and despatched an army, commanded by his eldest son, John, Duke of Normandy, to support Charles. This led to the outbreak of the Breton Civil War.
This army overran all of eastern Brittany apart from Rennes in the six months from September 1341 and captured John of Montfort. John surrendered on the granting of a safe conduct to Paris and back by John of Normandy, who escorted him. In Paris Philip proposed to John that he repudiate all claim to Brittany and his possessions there in favour of Charles of Blois, receiving an annuity and land in France in exchange. John declined, at which Philip withdrew his son's promised safe conduct and had John imprisoned. John's wife, Joanna of Montfort, was in Rennes with her two-year-old son, also named John, and the ducal treasury when news of John's capture arrived. Modern historians consider her to have been an energetic and effective leader, and she acted decisively and aggressively. She recalled the field army from western Brittany, joined it with some of the troops in Rennes and took command. She stormed the town of Redon and then moved to Hennebont. This was a small but strongly walled town with access to the sea. From there Joanna retained control of most of western Brittany and set up her infant son as the faction's figurehead and heir to his father's claim to the duchy.
Joanna despatched her senior counsellor, Amaury of Clisson, to Edward III in England with a large sum in cash to encourage English military intervention. The Montfortist cause was soon being supported by Edward III as an extension of the war with France. This was the start of Edward's "provincial strategy", by which he sided with French vassals of Philip in their disagreements with him: this promoted Edward's claim to be the rightful king of France and potentially created military allies. Strategically Edward had the opportunity to set up a ruler in Brittany at least partially under his control, which would provide access to Breton ports, greatly aiding England's naval war and giving ready entry to France for English armies. However, English reinforcements took a long time to reach Brittany. This was partly because the Truce of Espléchin was in force between France and England. Ostensibly halting all fighting, in practice it prevented either country from deploying their main field armies, but was otherwise ill observed. It was due to expire on 24 June 1342.
On 15 April Charles moved on Rennes. The populace seized the commander Joanna had left in charge and surrendered. A little later a small English force of 234 men under Sir Walter Mauny arrived at Brest in western Brittany. They were despatched ahead of the main English force to garrison the main Breton ports; Mauny was probably under orders not to attack French forces until after the truce expired. Edward planned to land in Brittany himself in June with a substantial force, but had extreme difficulty in assembling ships. Mauny's force skirmished in the west to little effect, while Charles detached a force to besiege Vannes and marched the rest of his army on Hennebont.
The town contained a large garrison and morale was high. The French army arrived in late May. Some of the Spanish and Italian mercenaries pushed forward against orders and engaged a group of defenders formed up in front of the town gates. Charles's men were getting the worst of this fight and were unable to retreat; he was forced to send more men forward in small groups as they became available in an attempt to temporarily push back the Montfortists and allow his impetuous troops to retreat. The Montfortists also fed additional troops into the fight through the gate and Charles's attempt to facilitate an organised retreat failed; the whole attack was thrown back in disorder with many killed. The Montfortists pursued and burnt down most of the freshly established French camp. According to a contemporary account Countess Joanna rode through the suburbs in full armour encouraging the fighting men. She was later given the soubriquet "Flame of Brittany".
The next day Charles probed the town's defences and on the second day after arriving he ordered repeated assaults on the town, but they were all repulsed with losses. In early June the French dug in for a regular siege, in the hope that starvation would force the town's surrender. Charles moved his main force to Auray, leaving a small force of mercenaries, mostly Spanish, and several siege engines to carry on the siege at Hennebont under the command of Louis of Spain, an expatriate Spaniard who had previously been the admiral of France. Charles promised pardons and financial incentives in an attempt to win the Montfortists back to France. Some were inclined to seek what terms they could, but the majority of Joanna's council held firm. The betrayal by Philip of the safe conduct given to John of Montfort by Duke John caused a deep distrust of such pledges. At some point in June Mauny took his force up the estuary to resupply and reinforce Hennebont. By late June the besiegers had broken up their engines and left. Charles pulled back from his siege of Auray.
The French mobilised more than 10,000 men, possibly many more, in late June for the campaigning season and most of them were allocated to renewing the offensive in Brittany. By early July their impact was felt: Vannes agreed terms of surrender and fell to the French, the Montfortists in Auray ran out of food and abandoned the town at night, other lesser places also went over to the French. Joanna considered her position in Hennebont unsustainable and left it for Brest, where by August Charles was again besieging her. More than 2,000 English troops landed at Brest on 18 August, relieving the town and causing Charles to withdraw his army from western Brittany. The English then marched on Morlaix, a town on the north coast with strong fortifications and a secure harbour 50 kilometres (30 mi) from Brest, and besieged it. Charles was now aware that his force greatly outnumbered the English and he attempted to relieve Morlaix, but was defeated on 30 September at the battle of Morlaix. Edward III landed in Brest with a further 3,000 men on 26 October and besieged Vannes, only to agree the Truce of Malestroit on 19 January 1343. Hostilities did not recommence until June 1345. Joanna travelled to England where she went insane and ceased taking any part in the war; she was held in Tickhill Castle until she died in September 1374. It has been suggested that her confinement in Tickhill was political, rather than because of mental illness. Her husband predeceased her in 1345.
The Breton Civil War continued as a disjointed and inconclusive series of sieges, skirmishes and truces, frequently as part of the Hundred Years' War. The eastern and southern parts of Brittany were mostly held by the French, who continued to strongly support Charles of Blois, while western and northern Brittany continued to be largely Montfort or English controlled. Charles of Blois was killed in 1364 at the Battle of Auray and his army decisively defeated. The next year his widow, Joan of Penthièvre, signed the Treaty of Guérande, recognising John of Montfort's son as Duke of Brittany, which ended the war. The Hundred Years' War lasted until 1453, when it ended in a French victory.