Battle of Sluys (1340): Edward III's Naval Victory Over France

The Battle of Sluys was a naval battle fought on 24 June 1340 in the Zwin estuary, off the Flemish port of Sluis, at the start of the Hundred Years’ War. Edward III of England attacked a large French fleet gathered for an invasion of England and destroyed almost all of it. The victory gave England control of the English Channel for much of the next generation.

Background

When the Hundred Years’ War began in 1337, France held the advantage at sea. French ships and hired Genoese galleys raided English ports, burning Portsmouth in 1338 and Southampton in October 1338. Philip VI gathered a great fleet in the Zwin, near Bruges, to block Edward’s communications with his allies in the Low Countries and possibly to invade England.

Edward III had just been recognised as king of France by the Flemish towns, which needed English wool, and he had formally adopted the French royal title at Ghent in January 1340. He returned to England to raise money and troops and in June 1340 sailed from the River Orwell in Suffolk to return to Flanders.

The fleets

Numbers are uncertain. The English fleet probably had around 120–160 ships, most of them merchant cogs adapted for war, carrying men-at-arms and large numbers of archers. The French fleet, commanded by Admiral Hugues Quiéret and Nicolas Béhuchet, a royal treasury official, was larger, often put at about 200 vessels, including a squadron of Genoese galleys under Pietro Barbavera.

The battle

The French commanders arranged their ships in three or four lines across the mouth of the estuary and chained many of them together, turning them into fixed floating platforms. Barbavera reportedly urged them to put out to sea, where they could manoeuvre, but he was overruled.

Edward waited for the afternoon of 24 June, when the wind and tide were in his favour and the sun was no longer in his men’s eyes. The English ships came on in groups, with ships of archers placed between ships of men-at-arms. English longbowmen shot volleys onto the crowded French decks, and then the men-at-arms grappled and boarded.

The fighting lasted for hours and was extremely bloody. Ships captured earlier from the English, including the great cog Christopher, were retaken. Late in the day Flemish ships from Sluis attacked the French rear. Quiéret was killed, and Béhuchet was captured and hanged from the mast of his ship. Barbavera escaped with his galleys, but most of the French fleet was taken or sunk. Edward himself was wounded in the thigh.

Why the French lost

Medieval sea battles were fought much like land battles on floating platforms, with ships grappling each other so that soldiers could board. By chaining their ships and staying in the narrow estuary, the French gave up mobility and allowed the English to choose where and when to attack. The English advantage in archers, who could shoot faster and further than crossbowmen, then proved decisive.

Consequences

Sluys ended the immediate danger of a French invasion and made it much safer for English armies to cross the Channel. It allowed Edward to land in France at will, most famously in 1346 before the Battle of Crécy.

The victory did not bring a quick end to the war. Edward’s siege of Tournai later in 1340 failed for lack of money, and the Truce of Esplechin was agreed on 25 September 1340. French and allied ships continued to raid the English coast in later decades.

The battle was remembered as a source of English pride. The gold noble coin introduced in 1344 shows the king standing in a ship, and it has often been linked to Sluys, although the coin does not name the battle.

Myths and facts

A well-known story says no one dared tell Philip VI of the defeat until his court jester joked that the English were cowards because they had not jumped into the sea like the brave French. The anecdote is recorded by the English chronicler Thomas Walsingham but is best treated as a later tale rather than established fact.

The very high death tolls given by chroniclers, up to 20,000 or more French dead, are also doubted. Losses were certainly heavy because men in armour who fell into the water could not escape, but no reliable count exists.

Timeline

• 1337, May: The Hundred Years’ War begins.
• 1338, October: French and Genoese raiders burn Southampton.
• 1340, January: Edward III adopts the title of king of France at Ghent.
• 1340, 22 June: The English fleet sails from the Orwell estuary.
• 1340, 24 June: Battle of Sluys; the French fleet is destroyed.
• 1340, 25 September: The Truce of Esplechin pauses the fighting.
• 1346, July: Edward III lands in Normandy, beginning the Crécy campaign.

Why it matters

Sluys was the first great battle of the Hundred Years’ War and one of the most decisive naval battles of the Middle Ages. By winning control of the Channel, Edward III made the later English invasions of France possible.