Philip I of Flanders

Philip of Alsace (1143–1191) ruled Flanders, first as co-count with his crusader father Thierry from 1157, then alone from 1168. His marriage to Elisabeth brought him Vermandois and the Amiénois, and in 1167 they inherited the county of Vermandois. Flemish clothmaking depended on English wool, and he renewed a treaty with England in 1163. He once arbitrated between the kings of France and England, but war with the French crown later cost him Vermandois.

He died of disease at the siege of Acre in 1191 during the Third Crusade. Under his patronage Chrétien de Troyes wrote the unfinished Perceval.