Heiress of the counties of Nevers, Auxerre and Tonnerre at the death of her brother
William V in 1181, she was initially married to Olivier "Albus," lord of Grignon († 1181/84). When Olivier died,
King Philip Augustus arranged her marriage in 1184 - she was 14 - with
Peter II of Courtenay. In 1185, she and her husband Peter confirmed by charter the privileges of the church of
Saint-Étienne, and on 10 June 1190 they renounced by charter their hereditary rights in favor of Saint-Cyr. In 1191 they bought
Tonnerre of Agnes's mother, Mathilde of Burgundy. She died in 1192 or 1193, while her husband fought in the
Holy Land with the
Third Crusade, leaving a daughter,
Matilda (1188 † 1257), Countess of Nevers, Auxerre and Tonnerre, who married with
Hervé IV of Donzy († 1222) in 1199, and in 1226 with
Guigues IV of Forez († 1241). ==References==