Duchess of Aquitaine. Name variations: Agnes of Anjou; Agnes of Burgundy; Agnes, countess of Burgundy. Born c. 995 in Burgundy; died Nov 10, 1068, at convent of Notre Dame des Saintes, France; dau. of Otto William, duke of Burgundy, and Ermentrude de Roucy; m. William V the Grand or the Pious (d. 1030), duke of Aquitaine, 1019; m. Geoffrey Martel, count of Anjou, c. 1032 or 1040 (m. dissolved, 1050); children: (1st m.) William VII, duke of Aquitaine; another son; Agnes of Poitou (1024–1077), Holy Roman empress.
Born into the Burgundian ruling house, was extremely well-educated, even in the web of loyalties and enmities between the ruling feudal families of France; showed an ambitious nature and was pleased with her arranged marriage to the powerful Duke William V the Grand of Aquitaine (1019); upon William’s death (1030), struggled to gain control of the duchy for her children, because her husband’s eldest son (William VI) from a previous marriage had inherited title of duke; when her eldest son, also William, inherited the duchy upon William VI’s death (1038), retained her title as duchess and became regent of Aquitaine in his name; even after he came of age, played a principal role in the administration of the large duchy; married Geoffrey Martel, count of Anjou (c. 1040); when marriage dissolved and Geoffrey remarried (1050), refused to give up her dower lands that he had bestowed on his new wife (in the ensuing war, her son William VII died in battle); more or less withdrew from politics and turned to more spiritual endeavors, using her wealth to found the abbey of Notre Dame des Saintes and Abbey of the Trinity.