St Pol de Léon Bretagne France

Edward III’s Invasion of France and the Early English Victories in the Hundred Years’ War

As the Hundred Years’ War (1337–1453) continued, Edward III of England launched a major invasion of France, securing a series of military victories that would solidify English dominance in the early phases of the war.

Edward III’s Strategy and the Resumption of War

• Following the collapse of the Truce of Malestroit (1343) and the failure of the English offensive in Brittany (1345), Edward III renewed his efforts to assert his claim to the French throne.
• His strategy was based on:
  • Launching coordinated offensives on multiple fronts—in Gascony, Brittany, and northern France.
  • Using fast-moving cavalry raids (chevauchées) to devastate French lands and force Philip VI into battle.
  • Securing alliances with Flemish cities, which were vital trade partners of England and opposed French dominance.

Key English Victories in the 1340s

1. The Battle of Auberoche (October 1345)

• Fought in Gascony, this was an important English victory, demonstrating the effectiveness of longbowmenand surprise tactics.

2. The Battle of Crécy (August 26, 1346)

• Edward III led a major invasion of northern France, landing in Normandy in July 1346 with an army of 15,000 men.
• The English decisively defeated Philip VI’s larger force, marking a turning point in medieval warfare:
  • English longbowmen devastated the French knights, proving the superiority of ranged attacks over cavalry charges.
  • Many high-ranking French nobles were killed, including King John of Bohemia, reinforcing the weakness of the French military leadership.

3. The Siege of Calais (September 1346 – August 1347)

• After his victory at Crécy, Edward III laid siege to Calais, one of the most strategically important ports in France.
• The siege lasted nearly a year, ending when the starving defenders surrendered in August 1347.
• Calais remained under English control for over two centuries, becoming a key base for future invasions of France.

Impact of Edward III’s Victories

• The Battle of Crécy and the fall of Calais confirmed that England had the upper hand in the war.
• Philip VI’s inability to stop Edward’s advances led to growing unrest in France, as the nobility began questioning the effectiveness of the Capetian monarchy.
• The English longbow had proven itself as a dominant battlefield weapon, shifting military tactics away from heavy cavalry charges.
• England secured a foothold in northern France, from which it could launch further offensives.

Edward III’s campaigns in the 1340s demonstrated English military superiority, setting the stage for further conflicts and ensuring that the Hundred Years’ War would continue for decades to come.

The Winter Campaign in Northern Brittany and the Battle of Saint-Pol-de-Léon (1346)

During the winter of 1345–1346, William de Bohun, Earl of Northampton, conducted a long and difficult campaign in northern Brittany. His likely objective was to secure a harbor on the north side of the peninsula, possibly to serve as a landing point for Edward III’s main invasion force in the summer of 1346.

However, the English achieved little despite their efforts, as northern Brittany was the home region of Joan of Penthièvre, wife of Charles of Blois, and resistance from the local nobility and populace was particularly strong.

Change of Strategy: Edward III Chooses Normandy Instead

• Given the stalemate in northern Brittany, Edward III abandoned the idea of landing there.
• Instead, he chose Normandy as the staging ground for his 1346 invasion, launching the famous Crécy campaign.
• Northampton was recalled, and Thomas Dagworth was appointed as deputy lieutenant of Brittany, charged with maintaining English interests in the region.

The Battle of Saint-Pol-de-Léon (June 9, 1346)

• During a routine tour of English strongholds, Dagworth and his escort were ambushed near Saint-Pol-de-Léon by Charles of Blois and a French-Breton force.
• Dagworth’s men were nearly surrounded, but their longbowmen held their ground.
• Taking a defensive position on a hill, the English forces dug in and repelled repeated French attacks throughout the day.
• By nightfall, Charles of Blois was forced to retreat, leaving behind many wounded soldiers.

Impact and Consequences

• The Battle of Saint-Pol-de-Léon demonstrated once again the effectiveness of English longbowmen, even in outnumbered defensive engagements.
• Though Brittany remained contested, Dagworth’s victory helped stabilize English holdings in the region.
• Charles of Blois’ continued failures to decisively defeat the English-backed Montfortists weakened his position, keeping Brittany a key battleground in the ongoing conflict.

While Edward III shifted his focus to Normandy, the English position in Brittany remained intact, thanks to the success of Thomas Dagworth at Saint-Pol-de-Léon, ensuring that the Breton War of Succession would remain intertwined with the Hundred Years’ War.

John IV’s Return to Brittany and the English Intervention (1373–1377)

Between 1373 and 1377, Duke John IV of Brittany, still aligned with England, sought to regain control over his duchy after being exiled in 1373 due to the French occupation led by Bertrand du Guesclin and Olivier de Clisson. To achieve this, he secured military aid from John of Gaunt, Duke of Lancaster, who landed in Brittany with approximately 10,000 troops.