Odo II was the count of Blois, Chartres, Châteaudun, Champagne, Beauvais and Tours from 1004 and count of Troyes and Meaux from 1022. He twice tried to make himself a king: first in Italy after 1024 and then in Burgundy after 1032.

During the Middle Ages, the counts of Blois were among the most powerful vassals of the King of France.