History & Analysis

The Battle of la Roche Derrien: Sir Thomas Dagworth and a Victory Against the Odds

The Hundred Years’ War highlighted significant changes to both the nature of warfare, and to status and standing within late medieval English society. Prior to the more than century long conflict between England and France, the noble knight was both a symbol of chivalry and prestige, in addition to being the undeniable might and power of the battlefield. In a relatively short space of time, medieval military tactics took a substantial transformation. This change featured a dramatic transition of power in battle, with the ascendency shifting from the mounted knight, to the infantry. In addition, the importance and responsibility of a military man was no longer intrinsically linked to his social standing. The humble archer became a powerful weapon and thus a peasant became a respected member of the army, and likewise, an astute military commander could rise through the ranks on ability rather than birthright alone.

Although the origins of such changes took place prior to the Hundred Years’ War, the French were particularly slow learners and as such, were dealt some brutal and devastating lessons in a number of infamous battles. It should be noted, because the Scottish do deserve credit, that the English themselves were not exempt from underestimating the might of a predominantly infantry army; having being handed some good beatings by outnumbered Scottish forces in the lead up to the Hundred Years’ War. The English, however, did learn their lessons quickly, and they were not only able to adjust defensively, but also adopted, and evolved, elements of the Scottish tactics. The major battles of the Hundred Years’ War in which the English overcame the arguably more fancied French and their home-ground advantage, are excellent exemplars of the power of the dismounted army with men-at-arms supported by men wielding sharp pointy sticks – arrows in the case of the English, pikes in the case of the Scottish. However, the true strength of the tactical application of longbowmen en-masse, is arguably best demonstrated in some of the smaller engagements between the French and the English. One such example is discussed in my article on the Battle of Auberoche, and another is the feature of this article. Furthermore, the Battle of la Roche Derrien  includes a commander, who despite his lower rank, rose to significant prominence in his work defending King Edward’s lands in western France.

So, let’s get on to Brittany, Dagworth, and the Battle of la Roche Derrien…

Seeking to use an ongoing civil war to their own advantage, the English army of Edward III landed in the Duchy of Brittany in 1342 and went on to control much of the area. The rival claimants for the title of Duke of Brittany were: Charles of Blois, the nephew of the French king, and John de Montfort, a child of only eight who was being raised in England as the king’s ward. Brittany would arguably never feature as the key battleground of the Hundred Years’ War, but there were a number of important conflicts in the region, and a number of key figures rose to prominence doing the king’s work in duchy of western France.

At first glance, the duchy of Brittany would not appear a particularly valuable site for the English; it was not an ideal entry point into France, had only a few good harbours – none of which were controlled by the English at the time – and as Jonathan Sumption notes, it was arguably ‘vulnerable’, and ‘barren’. So, the question remains, why did Edward seek to control the peninsula? The simple answer – necessity. The strategic military importance of Brittany is not to be understated. Had a French presence been allowed to maintain a foothold in western Brittany, then communication with Bordeaux would have been nigh on impossible, thus meaning the continued defence of Gascony would be extremely difficult. Short of raising and deploying an army occupation similar in size say…to the one that marched around northern France annoying the French king, whose task would be to keep open the lines of communication (which would have been, to put it simply, economic suicide), Edward’s best option was to somewhat relinquish control of the area to independent contractors, loyal to the English crown. Such men would gain the revenues of the dukes of Brittany, and any associated profits of war, and therefore have significant reason to maintain a hold on the region, and in turn, the favour of the king*. In the late 1340s, Edward had two such commanders operating in Brittany, professional military entrepreneurs of sorts. Their task was to maintain control of the region, but they were required to do so with only limited forces at their disposal. One of these men was Sir Thomas Dagworth, who was responsible for controlling the entirety of the peninsula region of Brittany – with a force of approximately 500 men. A practical, cunning, and perceptive soldier; Dagworth had been involved in the governing of the duchy for the better part of the decade. He replaced the Earl of Northampton as commander in Brittany in 1347, and was particularly offensively minded once in control.

One of the chief problems for Dagworth was Charles of Blois. Not only was he the self-proclaimed Duke of Brittany, he was, as nicely described by Jonathan Sumption, ‘one of the ablest and most persistent enemies of the English cause’. In May/June 1347, Charles was besieging the English garrison within the castle at la Roche Derrien. The chief purpose of the siege was not to re-capture la Roche Derrien. Although the French war effort, and the surrounding villagers, would have been bolstered by such an outcome, Charles was most likely attempting to draw Dagworth into the field. The Englishman’s small force was the only thing keeping the majority of western Brittany (not including Brest) out of Charles’ grasp. Dagworth and his small English force of less than 1000 men – comprising roughly 400 archers – marched to relieve the garrison. Although Dagworth had limited troops at his disposal, his numbers could often be increased with the addition of Breton noblemen and independent companies in the region who were allied to the English cause. Upon hearing of the approach of Dagworth’s force, Blois had his men level the countryside in order to remove any possible cover for incoming the archers. The English were known to make use of natural barriers such as ditches and hedges to protect their archers in small engagements where large numbers of men-at-arms were not available. The Frenchman also ordered his men to dig large entrenchments surrounding their position.

The French force is believed to have been in the order of four to five times larger than the English, and as was customary at the time, they were bolstered by archers of their own in the form of mercenary Geneose crossbowmen. Charles had highly organised defensive tactics, and strict orders for his men to follow, as he was well aware of the potential damage that could be wrought by the now famous English longbows. The self-proclaimed Duke of Brittany had already suffered a defeat at the hands of Dagworth and a much smaller group of English archers in the Battle of Saint-Pol de Léon in 1346. Charles’ instructions had the French force divided into four smaller groups, and placed at specific points around the walls. The French positions were also separated by not only the defensive structures that Charles had his men construct, but also by natural obstructions such as woodland, marsh, and waterways. The Frenchman took the largest of the four bodies of men and positioned himself on the east of the town. When the English arrived, they had taken the time on their journey to plan both their movements, and attack, carefully. Dagworth sent a group of camp followers complete with carts and animals around to the western side of the town with instructions to make a particularly noisy diversion. The main English force was to attack to the east, and to further their element of surprise, they would begin their closing march at midnight.

The approach of the English was detected by Charles’ scouts, and the diversionary group failed in their plan. One of Charles’ strict orders was, that his men were to remain in place until attacked, and he had also warned them, and especially the scouts, to expect trickery from the English. Dagworth’s force approached the eastern encampment on foot, and launched an assault on Charles’ men. The confusion of the early morning darkness resulted in a disordered and violent battle. The French forces fared well initially, and the English were pushed back. A small number were even captured by the French, including Dagworth himself. As dawn gave light to the situation on the ground, the English garrison of la Roche Derrien, accompanied by a few hundred of the townsfolk, were able to assess the battle, and then rush from the gates to the aid of their allies. They launched an assault on the rear of Charles’ force and the French were overcome. Dagworth was rescued, and Charles taken prisoner; Sir Thomas himself transporting the French Duke, along with thirty of the ‘greater men of Brittany’ to the Tower of London. The victory would mark the finest military moment of Dagworth’s career.

Despite all his success, Dagworth’s life would come to an untimely end, and at the hands of a one-time ally – well, ally of sorts. As noted earlier, the control of Brittany at the time was chiefly the responsibility of two men. One, Sir Thomas Dagworth. The other, a dishonorable Breton by the name of Raoul de Caours. A ruthless man, but otherwise not particularly skilled soldier. Placed in charge of the area between Loire and Sèvre at Niort, de Caours was paid a yearly sum to do his duty, and offered financial incentives for capturing additional territory. Despite being in the service of Edward, de Caours’ function was to ‘serve the lord King at his own expense without asking him for anything’. After a dispute over the claim to a number of castles in the area he governed, de Caours showed his face by attempting to make a deal with the French. Essentially offering to swap sides and hand control of key areas to the King of France. His treasonous plans could not be put into action fast enough, and de Caours lost out. He would however gain some semblance of revenge on the English a year later, with a successful attack on Dagworth. The one time loyal English contractor rallied more than 100 men faithful to Charles of Blois, and ambushed Dagworth on the forest road between Auray and Vannes. Believing he was in what was essentially safe territory, Sir Thomas was only travelling with a small escort. Despite being blinded in one eye, and badly wounded in the process of the skirmish, Dagworth put up a passionate and ferocious defence. Ultimately his utter lack of men, and his mounting injuries, were too much to overcome, and Dagworth was run through, and killed on 20 July 1350. The cruel irony of his death exists in the motivation behind his killer. As noted earlier, de Caours was angered at claims to castles in the area in which he governed. The man who made such claims was a one-time poacher, Walter Bentley, who married the dame de Clisson, known as the Lioness of Brittany. He inherited her claims, and immediately sought to act on them, despite de Caours’ right to the lands by the agreement with the king, and the right of conquest. Bentley would go on to become Dagworth’s successor in Brittany.

* an interesting point to note, one that to do justice to simply would not fit in this article, is that the revenues of the dukes of Brittany were pitiful. A satisfactory system of taxation in the region didn’t exist even prior to the civil war. Essentially the money was made through a system of – as Sumption calls it ‘systemised plundering’ known as ‘ransoms for country’ or patis. This is a particularly interesting topic, I encourage you to read up on it. It may even be a topic for a future article for me.

– Jamie Gatehouse


  1. Featured image: The Battle of la Roche Derrien, Chroniques sire Jehan Froissart,  BNF Français 2643 f.180 r.
  2. Henry Knighton, Knighton’s Chronicle 1337-1396 (Oxford Medieval Texts), translated by G. H. Martin, Oxford: Clarendon Press, 1995.
  3. Jonathan Sumption, The Hundred Years’ War Volume I: Trial by Battle (London: Faber and Faber, 1999)
  4. Jonathan Sumption, The Hundred Years War Volume II: Trial by Fire (London: Faber and Faber, 2001)
  5. Jim Bradbury, The Medieval Archer (Woodbridge: Boydell Press, 1985)
  6. Christopher Allmand, The Hundred Years War: England and France at War c. 1300 – c. 1450 (Cambridge: Cambridge University Press, 1988)
  7. Andrew Ayton and Sir Philip Preston, The Battle of Crécy, 1346 (Woodbridge: Boydell Press, 2005)
  8. Clifford J. Rogers, The Wars of Edward III: Sources and Interpreations (Woodbridge: Boydell Press, 1999)
  9. Richard Barber, Edward III and the Triumph of England (London: Penguin Books, 2013)
  10. Anne Curry, Arms, Armies and Fortifications in the Hundred Years War (Woodbridge: Boydell Press, 1994)

If you liked this post, follow this blog and/or read the following blog posts:

The Battle of Crécy: The Language of Froissart and Tactics versus Etymology

The Battle of Auberoche: French Tactical Ignorance and Death for Dinner

The Battle of Bannockburn: English Arrogance and the Failure of Edward II

See our bibliographies on The Hundred Years’ War and Chronicle Editions.

2 replies »

  1. Brittany proved pivotal to the outcome of the Hundred Years War. It was important not only for the control of the sea lanes between England and Gascony, but also because it produced large numbers of armed men, as the Norman propagandist William of Poitiers observed with dismay in the 11th century.
    The decisive commander in the last decades of the HWT was Arthur III de Richemont, step-brother of Henry V of England. Commemorated in both England and France, he first served the French, but was wounded in the face and captured at Agincourt. After five years in an English prison, he agreed to serve Henry V, but after the king’s death he fell out with the Duke of Bedford over the Honour of Richmond and returned to French allegiance.
    Arthur arranged the Treaty of Arras which reconciled Burgundy with France, and he personally liberated Paris. Finding the French army unreliable, he retrained it and reformed the royal finances so they could support a standing army. He also created the Ordonnances. He was a strong proponent of artillery (to Napoleon’s later benefit) to soften up entrenched enemy positions, but this was not a factor in his victory at Formigny in 1450.
    Arthur’s nephew Duke Peter concluded the Battle of Castillon in 1453 with a cavalry charge causing Talbot;s death.


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