Who married Guy, Count of Flanders?

Guy of Dampierre (French: Gui de Dampierre; Dutch: Gwijde van Dampierre) (c. 1226 – 7 March 1305, Compiègne) was the Count of Flanders (1251–1305) and Marquis of Namur (1264–1305). He was a prisoner of the French when his Flemings defeated the latter at the Battle of the Golden Spurs in 1302.

Matilda of Béthune (died 8 November 1264), was a noblewoman from Artois who became countess of Flanders by marriage to Guy, Count of Flanders. She was heiress to her father's titles as Lady of Béthune, of Dendermonde, of Richebourg and of Warneton, as well as Advocatess of the Abbey of Saint Vaast at Arras, and the ruler of these states in 1248–1264. She was the mother of Robert, Count of Flanders, known as Robert of Béthune after his mother.

Isabelle of Luxembourg (c. 1247–1298) was a countess consort of Flanders and a marquise consort of Namur by marriage to Guy of Dampierre.