Jeanne “la Flamme”, Duchess of Brittany ~ A guest post by Simon Duits

Jeanne “la Flamme”, Duchess of Brittany ~ A guest post by Simon Duits

The Freelance History Writer is pleased to welcome historian Simon Duits as a guest on the blog with an article on French/Breton history. He writes extensively about the Middle Ages over at

During the chaos and confusion of the early Hundred Years’ War, a woman of fiery character led the Duchy of Brittany into battle. Strong-willed and courageous, her ferocious personality earned her the epithet “la Flamme” or, “the Flame”. Her name was Jeanne. She eventually even had the rare honor of having a war named after her, as the War of the Breton Succession also became known as the “War of the Two Jeannes” – one of them, of course, being Jeanne la Flamme. She spent much of her life pouring her energy into this cruel contest.

At the time, succession struggles were all the rage across late medieval Europe. Only four years before the Breton War erupted, the Hundred Years’ War had kicked off. Claimants from the Houses of Plantagenet and Valois went to war over the right to rule France. The late French king, Charles IV “the Fair”, had died without issue in 1328. Both his cousin – King Edward III of England (Plantagenet) – as well as his nephew – Count Philip (Valois) – claimed the French throne.

In 1341, the War of the Breton Succession erupted against this backdrop. The same thing that had happened to the French crown happened to the Duchy of Brittany: its ruler died without direct male descendants. Again, two factions went to war over the spoils of succession. Because the Hundred Years’ War was already raging across France, the Breton succession struggle soon became a proxy conflict of the larger theater of war between the English and the French. Both London and Paris intervened heavily in Brittany’s affairs during this period – and thus in Jeanne la Flamme’s life.

The War of the Breton Succession

Jeanne was born as Joanna of Flanders, daughter of the count of Nevers in western Burgundy and the countess of Rethel in northern Champagne. She carried the Flemish name on account of her brother, who became Count of Flanders in 1328 and steered the county into a pro-French course. Later, he was duly killed in the famous Battle of Crécy by the English.

In 1329, Jeanne married John of Montfort, the half-brother of the Breton duke. When this duke died childless, a contentious succession dispute dragged the entirety of Brittany into open war. The reason for this was that, for a long time, the late duke had declared his niece Jeanne de Penthièvre as heir. She was married to Charles of Blois, who would thus become the next Duke of Brittany. But, just before passing away, the dying duke indicated that his half-brother John of Montfort – Joanna of Flanders’ husband – should be his successor.

Upon the duke’s death in April, 1341, John and Jeanne predictably pressed their claim. Charles of Blois and Jeanne de Penthièvre naturally did the same. The stage for the War of the Two Jeannes was set.

John of Montfort and Jeanne of Flanders moved as quickly as they could. They secured the ducal treasury, hired some mercenaries, and – with this makeshift army – managed to subdue several castles and cities. Rennes, Vannes, Hennebont, Brest, Dol-de-Bretagne, and other strategic sites declared for the Montfortist cause. On top of that, an assembly of the citizens and lower nobility of the important city of Nantes acknowledged John as Duke of Brittany. John and Jeanne enjoyed a clear first mover advantage.

Jeanne and John are declared Duchess and Duke of Brittany by the inhabitants of Nantes. (15th century, Public Domain)]

However, the high nobility, who controlled roughly two-thirds of the duchy, had not chosen sides yet. One of the major Breton houses were the Penthièvres – the House of the “other Jeanne”, wife of the opposing claimant Charles of Blois. To make matters even more complicated, Charles of Blois was a cousin of Philip of Valois – the new King of France and the very reason for the commencement of the Hundred Years’ War. In response, John of Montfort made a fateful decision that plunged the Breton dispute into the larger Anglo-French conflict, and sought the assistance of the king of England to balance things out.

The English Connection

John met with Edward III at Windsor. The English king pledged to support the Montfortist cause with troops and money in return for Brittany recognizing Edward as its lawful suzerain. This was precisely what the French feared. King Philip VI was not prepared to engage in a protracted proxy war over the Breton peninsula. The Hundred Years’ War already had enough fronts as is. Therefore, the French king summoned both John of Montfort and Charles of Blois to Paris. Philip VI wanted to settle this dispute without spilling any more blood.

The two claimants met during the Court of Peers meeting that King Philip VI had assembled. Quite unsurprisingly, neither side was willing to concede their point. So, the French king took a simple yet significant decision: he imprisoned John on the grounds of conspiring with the English and attributed the Duchy of Brittany to his cousin, Charles of Blois. One could be forgiven for thinking that this was an effective “quick and dirty” solution to one of the many challenges facing the French king at the time. Before the first English soldier had set foot on Breton soil, the succession war seemed already concluded.

But, in a spectacular turn of events, John of Montfort escaped his Paris prison, fled to Brittany and gathered his army. The French dreaded the idea of the English landing in Brittany, so Philip VI responded posthaste. He dispatched Charles of Blois to Brittany to settle the issue militarily once and for all. A French army over 7,000 strong appeared in front of the city walls of Nantes before the year 1341 was out.

The French made it very clear what they would do to treasonous Bretons if they didn’t surrender. They executed Montfortists taken prisoner in sight of the walls and catapulted the decapitated heads inside the city. The assembly that had declared for John only months earlier was enraged at the course of recent events and forced John to surrender. He gave in and was – once again – imprisoned in the Louvre in Paris.

Thanks to friends in high places, Charles of Blois had won the day. His uncle, the King of France, had personally made him Duke of Brittany. John’s brief stint as duke and his rapid downfall caused Montfortist morale to drop to an all-time low. Many members were considering the cause lost and regarded it futile to defy the French any longer. But Jeanne of Flanders, who had not been present at the siege of Nantes, was quite unwilling to surrender.

With her husband in prison once again, it fell upon her to lead the Montfortist cause. As one contemporary chronicler put it, “[with] the courage of a man and the heart of a lion”, Jeanne lifted her soldiers’ spirits and reassured them of the rightfulness of her husband’s claim. Bellicose as ever, under her leadership, the House of Montfort geared up for another round of fighting.

A Flame Erupts

With winter approaching (Charles of Blois conquered Nantes in November, 1341), hostilities ceased for the moment. This gave Jeanne of Flanders ample time to prepare for the next year of campaigning. She based much of her hope on the English reinforcements still making their way to Brittany. Consequently, she decided she would buy as much time as possible. Looking for a place to stall the advance of Charles of Blois into Brittany proper, she picked the castle of Hennebont on the southern Breton coast.

Jeanne at Hennebont

Throughout the 1341-1342 winter, the House of Montfort supplied, strengthened and reinforced the fort. In April, 1342, when the warm weather had returned, Charles of Blois duly besieged Hennebont castle. Jeanne of Flanders had successfully lifted troop morale over the winter, but when the French army appeared in front of the walls, she felt the need for steeling her army’s resolve.

Until then, she had strutted about, dressed as a duchess. Now, she took up arms, donned armor and personally led the castle’s defense to inspire population and garrison alike. Upping the ante, she personally spoke to the women of the castle, calling on them to “cut their skirts and take their safety into their own hands”. Immediately, they began breaking up the pavements and carried the stones to the battlements to be used as ammunition.

Over the following days and weeks, Jeanne kept a close eye from the castle walls on everything that happened inside the Blois camp. At a certain point during the siege, Jeanne noticed that it was lightly guarded. Most French soldiers happened to be scattered over the nearby woods, foraging. Spotting an opportunity to turn the tide, she gathered 300 cavalrymen and rode out on a great courser. Her force quickly overwhelmed the camp’s defenders, destroyed the tents of Charles of Blois, and torched the place.

This was probably the moment when Jeanne earned the nickname “la Flamme”. However, at least one Frenchman managed to sound the alarm and thousands of soldiers hurried back from the forest to defend their camp. As the fire raged all around, they managed to cut off Jeanne’s retreat route to Hennebont. With a stroke of genius, she turned her force around, left Hennebont for what it was, and retreated to Brest – on the western end of the Breton peninsula.

Charles of Blois immediately gave pursuit, but his larger force on foot could not keep up with Jeanne’s horseback pace. She thus arrived at Brest much earlier than Charles, gathered supplies and around 500 fresh troops, and went back to Hennebont by a different route. The French, to their chagrin, quickly realized what happened and returned to the castle to restart the siege. But Jeanne la Flamme had managed to resupply her army, destroy the enemy’s camp, and – most importantly – scored a crucial moral victory.

His Majesty’s Naval Service

Her theatrics thus bought Jeanne crucial weeks of time. But as the powerful French catapults kept hammering away at Hennebont’s walls day after day, the esprit de corps declined again. The initial effects of Jeanne’s antics, impressive as they might have been, faded. Once more locked up inside Hennebont castle, her advisors started to pressure her to surrender by the end of spring. In one of the keep’s upper chambers, a heated discussion erupted, as captain after captain tried to make the steadfast Jeanne change her mind.

Her officers were desperate to the point of rebellion, but when La Flamme looked out the window, a smile appeared on her lips. Ships had appeared on the horizon: the Admiral of the Northern Seas arrived at the head of an English navy. Jeanne would not need to surrender just yet. Evidently, the French had taken up too much time to capture Hennebont and now the window of opportunity had closed. Jeanne la Flamme’s sally and feigned retreat to Brest had undone much of the siege’s progress.

Whilst her captains are desperate to the point of insubordination, Jeanne witnesses the English fleet arriving and knows the tide has turned.

As the ships docked at Hennebont, King Philip’s nightmare had come true: the English landed in Brittany. The War of the Breton Succession had turned into a proxy conflict of the Hundred Years’ War. Overwhelmed by the arrival of the English, the French army lifted the siege and retreated. The tide of the war turned in favor of House Montfort again. But with her husband still in prison and two-thirds of Brittany loyal to her rival Jeanne de Penthièvre, the War of the Two Jeannes was far from over.

Jeanne la Flamme decided she needed more help and went to England herself. King Edward III was a bit preoccupied with hosting feasts and tournaments, but – after a long wait – finally granted Jeanne an audience and promised her further assistance. She set sail back to Brittany with a fine collection of English men-at-arms. However, near Guernsey, they were beset upon by a French fleet that had been lying in ambush. The French grappled the English ships and fierce hand-to-hand combat ensued. Fortunately for the English, Jeanne la Flamme was aboard: she raged across the decks with a glaive and allegedly slew many enemies. By the end of the day, the fight had failed to deliver a clear result and the French retreated. Jeanne and her allies continued towards Brittany.

Edward, The King

Around this point in time, the role England began to play in the War of the Breton Succession became a mixed blessing for the Montforts. Although it had been John of Montfort himself, and – after him – Jeanne la Flamme too, who had personally requested reinforcements from king Edward III, the Breton conflict now assumed proportions greater than ever intended. English commanders – not in the least Edward himself – increasingly influenced Breton affairs, relegating Jeanne la Flamme to a background role.

For instance, King Edward landed at Brest and, over the following years, basically took over the Breton conflict. The king enjoyed mixed results in the duchy, however, and a truce was concluded in 1343. Tellingly, the treaty failed to deliver a definitive answer to the underlying question of the Breton succession. At least, the truce allowed John of Montfort to be released from the Louvre prison. Jeanne and John could reunite after two eventful years.

They went to England to make further preparations for continuing their struggle when the truce ran out. When hostilities resumed in 1345, John of Montfort gathered another English army, fought against the French and died – of all places – at Hennebont. Jeanne la Flamme and her infant son were still in England, ready to carry on the succession struggle, but now Edward had had enough. With John of Montfort out of the way, the English king wanted the Breton front for himself. He ordered Jeanne la Flamme to be confined to Tickhill Castle, in northern England.

She was charged with mental illness, although no evidence of that ever surfaced. In essence, Edward used her as a figurehead claimant to augment his own offensive. The king carried Jeanne’s claim in theory, but – in practice – wanted to conduct the war without Montfortist meddling.

La Flamme’s Legacy

Over the next two decades, the English steadily gained the upper hand in their Breton theater of war. In the end, Edward allowed Jeanne la Flamme’s (now adult) son John to leave Tickhill and move to Brittany. To further illustrate the balance of power, Edward III instructed him not to marry or wage war – fundamentally, not to do anything – without consulting him first. Perhaps taking after his strong-willed parents, John tried to strike a deal with Charles of Blois anyway by proposing to divide Brittany between them. But the “other” Jeanne, Charles’ wife, would have nothing of it and implored her husband to crush the young Montfort claimant.

Matters quickly came to a head after that. In 1364, an Anglo-Breton force of around 6,000 strong clashed with a French army of roughly 4,000 in strength. Jeanne la Flamme’s son commanded the English center; Charles of Blois the French. Men-at-arms and knights of both sides marched towards each other and, without any maneuvering or tactical tricks, engaged in ferocious and sanguine direct combat. After more than twenty years of war, both armies wanted a decisive result there and then. John, as well as Charles, gave orders not to take any prisoners and to leave as few survivors as possible.

The setup worked, as Charles of Blois was killed in the ensuing melee. His wife Jeanne de Penthièvre tried to carry on his claim like Jeanne la Flamme had done for the Montfortists, but the Blois cause collapsed soon after the battle. The next year, a comprehensive peace treaty was concluded to end the War of the Breton Succession. The son of John of Montfort and Jeanne la Flamme was finally and universally recognized as John IV, Duke of Brittany.

Still locked up in Tickhill Castle, Jeanne la Flamme only learned of these developments sometime later. With her son now wearing the Breton ducal crown, she was of no value to the English king anymore. Edward did not allow Jeanne to leave. Despite having fought so hard for the Montfortist cause, Jeanne la Flamme never set foot in Brittany again. But her efforts were not in vain: she spent the last 10 years of her life – albeit under house arrest – in the knowledge that her son’s rule over the duchy was safe and secure.

Further reading: “The True Chronicles of Jean le Bel, 1290 – 1360” by Jean le Bel (transl. Nigel Bryant); “Joanna of Flanders: Heroine and Exile” by Julie Sarpy; “Women of Medieval France”, Chapter IX, by Pierce Butler; “The Creation of Brittany: A Late Medieval State” by Michael Jones; “Princely Power in Late Medieval France. Jeanne de Penthièvre and the War for Brittany” by Erika Graham-Goering; “The Hundred Years War, Vol 1: Trial by Battle” by Jonathan Sumption.