Battle of Sluys

The Battle of Sluys was fought on 24 June 1340. King Edward III of England intended to sail his fleet up the River Zwin to Bruges in order to meet with his allies for a land campaign. This was the result of delays in the English departing: the original plan having been to embark in April, to sail to Sluys and disembark their. Edward’s initial plan was hampered by two issues. First, the reluctance of merchant ship owners to surrender their cogs [merchant ships] for his expedition, an ongoing issue resultant from the regular delays or failure of the crown to compensate them for the requisitioning. Secondly, the French strategy changed. They had been engaged in raiding the south coast of England. Now, they adapted their strategy and blockaded the port of Sluys, intending to cut off the English fleets point of disembarking.

The navies

French documents suggest that their force comprised 202 vessels: 6 galleys, 7 royal warships, 22 oared barges and 167 merchant vessels. It carried a force of 19000 men. However, only 600 of these were men-at-arms. The Fleet was called the Great Army of the Sea and was commanded by Hugues Quiéret, the Admiral of France, and Nicolas Béhuchet, the Grand Constable of France. The galleys were fast moving vessels which were ideal for raiding. The warships were state of the art for the day and formidable military vessels. The merchant vessels were requisitioned and were capable of carrying large numbers of men. The French had a large number of crossbowmen within their force.

The English navy was mainly requisitioned merchant ships. King Edward III also had 3 warships of his own, including his flagship Thomas of Winchelsea. As with the French, the majority of these vessels were ideal for carrying large numbers of troops, or supplies. The English force is estimated to have been between 120 and 150 vessels. The force that King Edward carried to Sluys included 1300 men-at-arms and 1000 longbowmen.

Full Page image. Froissart's Chronicles. Battle of Sluys 1340
British Library image of Froissart’s Chronicle entry for the Battle of Sluys


The Battle of Sluys

The French had chained their ships together to blockade the port of Sluys. The English fleet used a ruse of a faked retreat to lure the French into disengaging the chains and attempting a pursuit. Upon this, the English then went on the offensive. Using artillery from the cogs and warships, along with use of longbowmen, an aerial assault on the French fleet was undertaken. This was hugely effective. Longbowmen can loose arrows faster than the French crossbowmen could unleash their bolts: archery expert Robert Hardy estimates this may have been up to three times the speed. The range of a longbow is also considerably further than that of a crossbow, enabling the English to inflict damage before they were in range of the enemy. The effectiveness of the aerial assault meant that the English fleet was able to close in on the French vessels. The French were tightly packed and had the wind against them, making manouvres difficult. The advantages that galleys often enjoyed were therefore overcome. Edward’s fleet was able to close in and engage in boarding the French ships. With a larger number of well trained men-at-arms and ongoing volleys of arrows from the longbow men, the English were able to inflict significant damage to the French force: who had no option of retreat or reforming. The result was a decisive victory for the English, with most of the French fleet being captured, or sunk. The French galleys and 17 other ships managed to escape.

Losses in the Battle of Sluys

Sea battles have little opportunity for the taking of prisoners and there typically is no quarter given. As a result, most of the French force was killed. Estimates range from 10000 to 20000 French dead. This included Béhuchet who was hanged from the mast of his own ship, and Quiéret who was captured and soon afterwards beheaded by the English. English losses were far fewer. Estimates suggest in the region of 600 deaths, of which 4 were men-at-arms.


Despite the fleet having been devastated, King Philip of France had the resources to rebuild. A month later 30 English merchant ships were seized and their crews thrown overboard. Later in 1340 a series of raids were launched along the south coast of England which caused significant damage to some ports. The main medium term concern for the French was the impact that it had on merchant shipping, as the loss of so many ships and sailors meant that the fishing and trading ports of Northern France were severly lacking in ships and experienced crews.

Contemporary Accounts of the Battle of Sluys

The Florentine Chronicler Giovanni Villani heard of the build up to the Battle of Sluys through his extensive network of contacts. His account suggests that the Flemish urged caution but that King Edward III opted to go straight on the offensive against the French armada at Sluys.

That year, 1340, on the day of St. John the Baptist, the 24th of June, the good King Edward III, King of England, arrived in Flanders at the port of Zwin with 120 armed ships, with 2000 noblemen-at-arms and an infinite number of common people, including many English archers; and he found the fleet of the King of France, which was 200 ships with 30 armed galleys amd armed barges, of which the admiral was Barbanero di Portoveneri, a great pirate, who had done great harm to the English and Gascons and Flemings along their coasts, and seized the isle of Cadzant, which was opposite Zwin, and pillaged and burned and killed over 300 Flemings. The people of Bruges, learning of the arrival of the King of England, sent their ambassadors to Sluys begging him for God’s sake and for his love of them that not give battle against the armada of the King of France – which was as large again as his fleet, and moreover included the Genoese galleys – and that he wait for two days and rest his men, for at that moment they were arming a hundred ships of good men to aid him, and he would have a certain victory. The valiant king did not wish to wait, but had his men-at-arms and sergeants arm themselves.

Giovanni Villani, contemporary


Bataille de l'Écluse (1340)
Bataille de l’Écluse (1340)

The sea battle itself is well documented. The best known account is that of Jean Froissart. Illustrations from versions of his chronicle are well known and provide us with a visualisation of the manner of sea warfare of the time. An extract from his written account is below:

Fierce fighting broke out on every side, archers and crossbowmen shooting arrows and bolts at each other pell-mell, and men-at-arms struggling and striking in hand-to-hand combat. In order to come to closer quarters, they had great iron grappling-hooks fixed to chains, and these they hurled into each others’ ships to draw them together and hold them fast while the men engaged. Many deadly blows were struck and gallant deeds performed, ships and men were battered, captured and recaptured.

Froissart’s Chronicles

Another execrpt shows the ferocity of sea warfare:

The battle then began very fiercely; archers and cross-bow-men shot with all their might at each other, and the men-at-arms engaged hand to hand. In order to be more successful, they had large grapnels, and iron hooks with chains, which they flung from ship to ship, to moor them to each other. There were many valiant deeds performed, many prisoners made, and many rescues. The Christopher, which led the van, was recaptured by the English, and all in her taken or killed. There were then great shouts and cries, and the English manned her again with archers and sent her to fight against the Genoese.

This battle was very murderous and horrible. Combats at sea are more destructive and obstinate than upon the land, for it is not possible to retreat or flee—everyone must abide his fortune and exert his prowess and valor. Sir Hugh Quiriel and his companions were bold and determined men, had done much mischief to the English at sea and destroyed many of their ships; this combat, therefore, lasted from early in the morning until noon, and the English were hard pressed, for their enemies were four to one, and the greater part men who had been used to the sea.

Froissart’s Chronicles

A miniature of the battle from Jean Froissart's Chronicles, 15th century. BNF, fr. 2643 fol. 72.
One of several Miniatures extracted from artwork in Froissart’s Chronicle.

The French Chronicle of London, written in the early 1340s, recorded the Battle of Sluys:

On Friday morning, our King saw his enemies on the sea, and said “because Our Lord Jesus Christ was put to death on a Friday, we do not wish to spill any blood on this day.” At that time the wind had been in the east, before the King took to the sea, for a whole fortnight; but by the grace of the Almighty the wind immediately turned to come from the west. Thus by the grace of God the King and his fleet had the wind and weather as they wished them. And so they sailed forward up until the break of day at sunrise, and he saw his enemies so formidably prepared that it was too horrible to look at, for the ships of France were so strongly bound together with large chains, equipped with castles, wooden breastworks, and barriers. But nevertheless Sire Edward our King said to those who were around him in the English fleet: “Good lords and my brothers, do not at all be dismayed, but be entirely of good comfort; and he who for me today gives battle will be fighting in pursuit of a just cause, and will have the blessing of God Almighty, and each shall keep whatever he may gain.” And as soon as out King finished giving this speech, everyone was eager to seek to avenge him against his enemies. And then our sailors drew the sails to half-mast, and drew up their anchors as if they were goinf to flee; and when the navy of France saw this they unfastened their great chains in order to pursue us. And immediately our ships turned back against them, and the melee began with trumpets, nakers, viols, tabours, and many other musical instruments. And then our King, with 300 ships, vigourously attacked the French with 500 large ships and galleys; and eagerly all our men put forth great diligence in order to give battle to the French. Our archers and crossbowmen began to fire so thickly, like hail falling in winter, and our artillerymen shot so fiercly, that the French were unable to look out or to hold their heads up. And while this fight lasted, our Englishmen entered their galleys with great force and fought hand to hand with the French, and cast them out of their ships and galleys. And always our King, in the cog Thomas of Winchealsea, inspired them by fighting strongly with his enemies. And at the hour of mid-morning a ship of London, belonging to William Hansard, came to them; it did much good work in the battle. For the battle was so fierce and so dire, that as the attack lasted from noon all day and all night, and the next day up until the first hour, and when the battle was won, no Frenchman remained alive except for Spaudeville, who fled with 24 ships and galleys.


Jstor – The Effects of the Battle of Sluys upon the Administration of English Naval Impressment, 1340-1343

Jstor – Tactics, Strategy and the Battle of Sluys

Jstor – The Organisation of Impressed Fleets


Oxford Reference

Warfare History Network


Navy History

Royal Museums Greenwich

British Battles


Bataille de l’Écluse (1340). Stated as Public Domain on Wikimedia Commons, here. No detailed attribution, other than the French name for the Battle of Sluys, which is Bataille de l’Écluse (1340).  Wikimedia’s source is this link.

Miniature from Froissart’s Chronicles. This Public Domain image is sourced from Wikimedia. It is a modern cropped image taken from a photograph of the original artwork. Click on the image for the source file and full details.

Miniature from Froissart’s Chronicles. This Public Domain image is sourced from Wikimedia. It is a modern cropped image taken from a photograph of the original artwork. Click on the image for the source file and full details.

Photograph of the page in Froissart’s Chronicles that covers the Battle of Sluys. Sourced from the British Library. The BL retain copyright but permit non-commercial usage so long as credit is given. Click on the image for the source file and full details.

Dan Moorhouse

Dan Moorhouse graduated in History and Politics and has since undertaken postgraduate studies in Medieval History and Education. Dan is a member of the Royal Historical Society and has previously been a member of the Historical Association’s Secondary Education Committee. Dan’s early publishing was in the Secondary School History Education field. This included co-authoring the Becta Award shortlisted Dynamic Learning: Medicine Through Time series for Hodder Murray and contributing to the Bafta Award winning Smallpox Through Time documentary series by A former teacher, Dan now concentrates on research and writing, predominantly in Medieval English history. Books by Dan Moorhouse On this day in the Wars of the Roses On this day in the Hundred Years War

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