The Battle of Sluys was fought in 1340 between France and England. The English fleet comprised of merchant vessels called cogs which were requisitioned into the service of King Edward III. The French fleet comprised of a larger number of vessels, some of them contributed by their Genoese allies.
The battle was a decisive victory for the English and the French fleet was completely destroyed, ushering in a brief period of English supremacy in the English Channel.
The Battle of Sluys was a part of the Hundred Years’ War between England and France. The war between the two kingdoms began over the dispute of succession to the French throne and the status of English territories in Aquitaine.
Although most of the confrontations during the war took place on mainland Europe, some of the naval battles took place in the English Channel. The French initially had supremacy over the English in naval warfare but England was soon able to gain the advantage by organising a merchant fleet and modifying it for military use.
Edward III of England lead the English naval effort at the Battle of Sluys while the French fleet was overlooked by commanders Quieret and Behuchet. Since England didn’t have a proper navy, a large number of merchant cogs were requisitioned by the King.
The cogs had the advantage of being higher and able to carry a larger number of soldiers. They were also more heavy-built and had a decided advantage in close combat. To make their advantage more certain, Edward had the cogs set up with wooden towers at both ends, allowing archers to range their arrows from a fair height on to French ships. In total, the English cogs numbered at around 120 to 150 while the French fleet comprised of 190 to 213 ships.
The French tactic at the Battle of Sluys involved chaining together two to three ships into single units in defence formations. The English fleet countered this by sending three cogs at a time against each French formation. Two of the cogs would rain down arrows on to the French ship while the men-at-arms from the third would rush to board the French vessel and engage in combat.
English archers and the overall English strategy proved decisively advantageous while the French decision to chain together vessels proved fatal to them. The fighting continued for an entire day and the night, resulting in heavy losses on both sides. Ultimately, the French fleet was destroyed while only two English ships were captured by France’s Genoese allies.
In the aftermath of the Battle of Sluys, French naval might in the English Channel effectively ended for the time being. However, King Edward of England didn’t press his advantage and rather than building a proper navy, continued requisitioning merchant vessels as per his military needs. Since the crown often couldn’t pay the merchants for their vessels, the strategy made Edward unpopular with English merchants. On the other hand, the French took advantage of the lack of a proper English navy and by the end of Edward III’s reign, a proper French fleet was back in full strength and active in raiding English coasts once again.