Siege of Tournai, 1340

The Siege of Tournai began on 23 July 1340, during the opening campaign of the Hundred Years War. Following the English victory at the Battle of Sluys on 24 June, Edward III and his Flemish allies turned against French-held territory in the north. Tournai, a strongly fortified town loyal to Philip VI, became the principal objective.

The siege lasted for two months. Edward failed to capture the town, while Philip VI brought a relief army into the area without forcing a decisive battle. The campaign ended with the Truce of Espléchin on 25 September, leaving Tournai in French hands and exposing the difficulties of sustaining Edward’s coalition through a prolonged siege.

Section of 15th century artwork depicting the 1340 Siege of Tournai. — Siege of Tournai. Cropped from illustration in Froissart’s Chronicles. Full image here.

The Siege of Tournai, 1340

The Prelude: Sluys and Saint-Omer

On 24 June 1340, the English fleet defeated the French at the Battle of Sluys. The French suffered heavy losses in ships and men, while the English victory made it easier for Edward to move men and supplies between England and the continent. It also strengthened his position among his continental allies.

Edward and the Flemings subsequently planned a campaign against French positions in the north. Their first major objective was Saint-Omer, where Robert of Artois led an allied force. The attack ended in failure and heavy losses. Tournai then became the principal focus of the campaign.

The Defences of Tournai

Tournai was a strongly fortified French town with a substantial garrison. Philip VI reinforced the defenders with approximately 1,500 men-at-arms and 1,000 other foot soldiers. The size of Edward’s army is uncertain. Contemporary claims could place it as high as 120,000 men, but modern estimates cited by DeVries are considerably lower, at approximately 10,000–20,000.

The strength of the town’s defences meant that Edward could not expect a rapid victory. The siege would require sustained pressure against the fortifications while the defenders attempted to maintain their supplies until relief arrived.

The Siege Begins

The siege began on 23 July 1340. Edward’s forces surrounded Tournai and attacked its defences using siege engines and artillery, while the garrison replied from the walls and towers.

Contemporary accounts provide evidence for the use of cannon during the siege. Cannon were employed by the besiegers and defenders, alongside more traditional siege engines. Their use illustrates the growing presence of gunpowder artillery in fourteenth-century warfare, although it did not make a strongly defended town easy to capture.

The organisation of Edward’s army is also visible in surviving administrative evidence. Two writs issued at Tournai on 29 September 1340 identify Reginald, Lord Cobham, as mareschal del host, or marshal of the king’s army. The documents provide direct evidence for the organisation of Edward’s royal host during the campaign.

Famine and Attrition

The longer the siege continued, the more serious the shortage of food inside Tournai became. Contemporary accounts describe rising food prices and increasingly severe conditions for the inhabitants and garrison. Horses and other animals were consumed as available supplies diminished.

The pressure was not confined to the town. Edward’s army also required regular supplies, and maintaining a large force in the field placed increasing demands on his allies and resources. Raiding and control of the surrounding countryside became important to the ability of both sides to sustain their forces.

The siege consequently became a contest of endurance. Tournai had to hold out until relief arrived, while Edward needed to maintain his army long enough to force a surrender.

Philip VI and the Relief Army

Philip VI assembled a relief army and moved towards Tournai. The arrival of the French force created the possibility of a major confrontation between the two kings, but no decisive battle followed.

For Edward, the situation was increasingly difficult. Tournai had resisted the siege, the French army remained nearby, and the cost of maintaining the English and allied forces continued to increase. The French, meanwhile, had not broken the siege through a direct attack on Edward’s army.

Contemporary writers interpreted this situation differently. French accounts could present Philip’s conduct as successful, while English and Low Countries accounts could emphasise Edward’s difficulties or Philip’s refusal to risk a decisive engagement.

The Truce of Espléchin

The siege ended with the Truce of Espléchin on 25 September 1340. Jeanne of Valois, Countess of Hainault and a close relative of both royal families, was associated with the negotiations that brought the opposing sides to an agreement. The precise sequence of the negotiations and the extent of her influence vary between the contemporary accounts.

The truce allowed Edward to withdraw without capturing Tournai. Philip VI likewise avoided the risks of a major battle. The immediate campaign therefore ended without either side achieving all of its objectives.

Jean de Bel captured the uncertainty surrounding the result:

Thus each of the parties involved in the battle attributed the honour [of victory] to himself, over which many debates and arguments were held…

The differing accounts are significant. French, English and Low Countries writers did not agree on where responsibility for the outcome lay, or on which side had gained the greater advantage.

Edward III’s Financial Problems

The military difficulties at Tournai were accompanied by serious financial problems. Edward’s continental campaign depended upon commitments to his allies and soldiers, but the costs of maintaining the army had become increasingly difficult to meet.

Financial pressure was an important factor in Edward’s decision to accept the settlement. Jan de Klerk’s account makes the problem particularly explicit:

The king thought in his mind that his counsel was in part truly good
as he had no silver or gold
by which he might pay his soldiers if they were to continue this war…
…so he knew well that the need was there that he agreed to.

The financial consequences continued after the truce. Edward had incurred substantial debts during the campaign and needed to return to England to obtain further funds. The difficulties of financing the expedition also placed pressure on his relationship with his continental allies.

Edward Leaves Flanders

The Flemings had expected the campaign to contribute to the recovery of Lille, Douai and Béthune, while Edward needed their continued military and financial support. These expectations were increasingly difficult to reconcile after the failure to capture Tournai.

Edward remained in the Low Countries for a time while arrangements were made concerning his financial obligations and the alliance. He then sailed for England on 27 November 1340, arriving three days later. His departure brought the campaign to an end.

Tournai remained in French hands. Edward had not suffered a decisive battlefield defeat, but he had also failed to achieve the principal objective of the campaign. The siege had instead exposed the importance of fortifications, artillery, food supplies, coalition politics and finance in fourteenth-century warfare.