Guy I, Count of Blois

Guy I of Châtillon, Count of Blois (died 12 August 1342), son of Hugh II of Châtillon and Beatrix of Dampierre, was Count of Blois and Lord of Avesnes 1307–1342.
In 1310, he married Margaret of Valois, daughter of Charles of Valois and sister of Philip VI of France. They had three children:
He took part in the expedition of Louis X of France against his uncle Robert III of Flanders in 1315, and in the early stages of the Hundred Years' War.