The siege of Tournai (23 July - 25 September 1340) occurred during the Edwardian phase of the Hundred Years' War.

Edward's crushing naval victory at the Battle of Sluys allowed him to land his army and carry out his campaign in northern France.

When Edward landed he would be joined by Jacob van Artevelde, Flanders' semi-dictatorial ruler who had gained control of the County in an insurrection.

10,000 to 15,000 Flemings and 1,000 English longbowmen would launch a chevauchée under the command of Robert III of Artois and the remainder of the coalition forces under Edward would go on to besiege Tournai.

[7] Edward's forces were supported by Flemish militia led by Jacob van Artevelde, the armies of William II, the Count of Hainaut and the Holy Roman Empire sent by Louis IV.

These siege engines had little effect due to Tournai's modern walls and Edward soon decided to secure the city through famine.

As Phillip drew closer the men of Brabant and Hainaut threatened to mutiny if they weren't paid.

Edward returned to England bankrupt, blaming the failure of the campaign on his ministers for failing to send him money.

[5] Also, in response to the failure suffered by the English under John Chandos, he reportedly sacked and burned nearby towns and smaller castles.