Battle of Zierikzee

The County of Zeeland was an area that had been contested between the Count of Flanders and the Count of Holland since the 11th century. Originally granted in 1012 by Emperor Henry II to the count of Flanders Baldwin IV, by 1076 the area had become part of Holland but under Flemish overlordship. After the Flemish victory in the battle of the Golden Spurs, the Flemish attacked John II Avesnes, count of Holland, Zeeland and of Hainaut and conquered Lessines. The House of Dampierre and the House of Avesnes had been involved in a familial war for decades. In retaliation to the Flemish invasion of Hainaut John's son William plundered Cadzand.

In reaction to this raid, Guy of Namur, son of Guy I of Flanders, formed a fleet at Sluis, which sailed on 23 April 1303 to claim Zeeland for the Flemish. After Flemish landings near Arnemuiden and Veere the troops of William fled to Middelburg which surrendered on 9 May. After this the Flemings conquered the whole of Walcheren and several other islands. Only Zierikzee was held for the count of Holland. In July an armistice was arranged between the Flemings and the count of Holland.

Covered by an armistice in the north, the Flemings raised an army near Cassel, which entered France and attacked Saint-Omer, Terwaan and Tournai. In August Philip IV of France tried to raise a new army to counter this threat, but due to mutiny over arrears of pay he was forced to conclude an armistice until May 1304 with the Flemings, which was later extended to June. The armistice gave the French the opportunity to raise a new army in peace for the next campaigning season.

In the Spring of 1304 the armistice between the Flemings and Holland was broken. William attacked and defeated the Flemings near Castle Blodenburg. A fleet led by William and his uncle Guy of Avesnes, bishop of Utrecht however was defeated by the Flemings, the bishop being captured. After this victory, the Flemings invaded Holland and Utrecht. Seeing the Flemish success John II, Duke of Brabant then joined the Flemish cause. Dordrecht, led by Witte van Haemstede, a bastard son of count Floris V, brought the cities of Holland to the side of William and the Flemings retreated. After this Zierikzee, which was still held by Holland, was besieged.