Guy de Dampierre

Guy of Dampierre riding a horse. His surcoat bears the arms of the county of Flanders
Spouse(s)	Matilda of Béthune Isabelle of Luxembourg
Noble family	House of Dampierre
Father	William II of Dampierre
Mother	Margaret II of Flanders
Born	c. 1226
Died	7 March 1305(1305-03-07) Compiègne

Guy of Dampierre (Dutch: Gwijde van Dampierre) (c. 1226 – 7 March 1305, Compiègne) was the Count of Flanders (1251–1305) and Marquis of Namur (1268–97). He was a prisoner of the French when his Flemings defeated the latter at the Battle of the Golden Spurs in 1302.

Guy was the second son of William II of Dampierre and Margaret II of Flanders. The death of his elder brother William in a tournament made him joint Count of Flanders with his mother. (She had made William co-ruler of Flanders 1246 to ensure that it would go to the Dampierre children of her second marriage, rather than the Avesnes children of her first.) Guy and his mother struggled against the Avesnes (led by John I, Count of Hainaut) in the War of the Succession of Flanders and Hainault, but were defeated in 1253 at the Battle of Walcheren, and Guy was taken prisoner. By the mediation of Louis IX of France, he was ransomed in 1256. Some respite was obtained by the death of John of Hainaut in 1257.

In 1270, Margaret confiscated the wares of English merchants in Flanders for non-payment of customs. This led to a devastating trade war with England, which supplied most of the wool for the Flemish weavers. The dispute was ended by a treaty agreed at Montreuil-sur-Mer on 28 July 1274, effectively abolishing customs charged on English merchants in Flanders. Even after her abdication in 1278, Guy often found himself in difficulties with the fractious commoners.