The fortifications were attacked and occupied by Odo II of Blois-Champagne in 1032 during the conflict after Rudolph's death.
He inherited some possessions in the region of Châteaudun and some historians have retrospectively called him "Count of Châteaudun."
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By a charter dated 25 October 876, Charles the Bald ceded Chaource, in Tonnerre, to Robert and Odo.
Odo the Great | Odo II of Champlitte | Odo II, Count of Blois | Odo, Earl of Kent | Odo of Cluny | Odo I, Margrave of the Saxon Ostmark | Odo I, Count of Blois | Odo I | Odo | Odo II |
In 1010 king Robert II of France along with Odo II, Count of Blois went to Rome to secure an annulment from Robert's second wife, Constance of Arles, Adelaide-Blanche's daughter by William I. Pope Sergius IV, a friend to the Angevin counts, upheld the marriage and additionally upheld Adelaide's struggle to maintain control of lands at Montmajour Abbey.
In turn for his support in the conflict with Count Odo II of Blois he received the northern Maurienne part of the County of Vienne, then a fief of the Vienne archbishops, as well as territories in the Chablais region and in the Tarentaise Valley, a fief of the Tarentaise archbishops at Moûtiers.
When the House of Bar, which ruled in Upper Lorraine, became extinct in 1033, with the death of his cousin Frederick III, Conrad made him duke of both duchies, so that he could assist in the defence of the territory against Odo II, count of Blois, Meaux, Chartres, and Troyes (the later Champagne).