Auguste Longnon

“ BLOIS, Countship of. From 865 to about 940 the countship of Blois was one of those which were held in fee by the margrave of Neustria, Robert the Strong, and by his successors, the abbot Hugh, Odo (or Eudes) , Robert II. and Hugh the Great. It then passed, about 940 and for nearly three centuries, to a new family of counts, whose chiefs, at first vassals of the dukes of France, Hugh the Great and Hugh Capet, became in 987, by the accession of the Capetian dynasty to the throne of France, the direct vassals of the crown. These new counts were originally very powerful. ”

“ His son Louis succeeded in 1191, took part in the fourth crusade, and after the taking of Constantinople was rewarded with the duchy of Nicaea. He was killed at the battle of Adrianople in 1205, in which year he was succeeded by his son, Theobald VI. the Young, who died childless. In 1218 the countship passed to Margaret, eldest daughter of Theobald V., and to Walter (Gautier) of Avesnes, her third husband.
The Châtillon branch of the counts of Blois began in 1230 with Mary of Avesnes, daughter of Margaret of Blois and her husband, Hugh of Châtillon, count of St Pol. ”