The Battle of Sluys – a summary

The often forgotten Battle of Sluys of 24 June 1340 was a major turning point in the Hundred Years’ War—a war that practically defined the direction that both England and France would follow for centuries.

The Players

The Hundred Years’ War began in 1337 after nearly three hundred years of disagreements between the Kings of England and the Kings of France over land claims on the Continent.  By the fourteenth century the Capetian dynasty of France had wrested away most of the previously held English territories on the Continent (such as Anjou and Normandy).  King Edward III of England was seemingly passed over in the dynastic succession of France when Philip VI was crowned King of France.  While Isabella (daughter of Philip IV of France), Edward III’s mother, was, by law, clearly not able to become the monarch of France, Edward III made the case that the throne could pass through a female line (thus making him King of France) rather than reverting back a generation to Philip VI, son of Charles, Count of Valois.

Through the 1330s, the French began to build their navy, especially in northern waters.  The English felt that their relations with the Low Countries (today, Belgium and the Netherlands) were threatened by this naval build up.  The Low Countries’ economy depended on cloth weaving and, at the time, the wool provided by England was crucial.  In May 1337, Philip seized Aquitaine and by October Edward took official steps to war.

The Early War

In early 1338, the French began raiding English coastal towns, such as Southampton and Portsmouth, and the Channel Islands.  Flanders rose in rebellion against the local count, Louis de Nevers, who supported the French side—the cloth trade was hurting as a result.  By the end of 1338, the Holy Roman Emperor, Ludwig of Bavaria, joined Edward III against the French.

Early in 1339, the French continued raids on the English towns of Folkestone, Harwich, Hastings, Southampton, Plymouth and Dover.  The English navy was steadily growing in strength as the English army marched ineffectively through France in September and October of 1339.  In February 1340, Edward III was officially crowned King of France in a ceremony in Ghent.

Combat at Sluys

By the summer of 1340, there had been no major battles fought between the English and French.  Following a failed attack on Cinque Ports by the French and the desertion of Italian mercenaries from the French navy, the French fleet in the Channel was severely cut back.  The English heard news of this and rushed to the French coast, raiding towns including Ault and Le Tréport.  Thus the stage was set for the first major battle of the Hundred Years’ War.

The French and English fleets met outside the town of Sluys (today spelled Sluis; L’Ecluse in French) on 24 June 1340.  The English fleet was somewhat outnumbered, but they had advantageous positioning.  Edward himself commanded the English forces and was wounded in the battle.  Combat lasted the better part of the day extending into the evening.  The two French commanders were both captured and killed in an overwhelming victory for the English forces.  The English suffered a few thousand casualties whereas the French suffered nearly 20,000 casualties.  The English captured what French ships were not destroyed by the battle.  The English losses were minor enough that they could assume dominance of the English Channel.

Significance of the Battle of Sluys

The Battle of Sluys was a major turning point early in the Hundred Years’ War because it virtually destroyed the French fleet.  The majority of French ships had been amassing to invade England.  However, the English victory at Sluys ensured that a French invasion would never come to pass.  Thus, the majority of combat throughout the Hundred Years’ War occurred in France.  To a nation whose history is full of important naval victories, the English victory at Sluys is an early and tremendously important maritime success that should be remembered.

Sarah Jane Bodell