Odo I, Count of Blois

Odo I (also spelled Eudes) (c. 950 – 12 March 996), Count of Blois, Chartres, Reims, Provins, Châteaudun, and Omois, was the son of Theobald I of Blois and Luitgard, daughter of Herbert II of Vermandois. He received the title of count palatine, which was traditional in his family, from King Lothair of West Francia.

Like his relations, the counts of Vermandois, he remained faithful to the Carolingians against the Capetians. Following the war between his father and Odalric, Archbishop of Reims, over the castle of Coucy, he received the castle to hold it from the archbishop.

In the 970s, in the wars for control of Brittany, he subjugated the county of Rennes and Count Conan I affirmed the rights of his family in the region. Around 977, his father died and he succeeded in his counties.

In 988, he assisted Charles of Lorraine in taking Laon. In 991, he abandoned the Lorrainers at Dreux and besieged Melun, belonging to Bouchard the Venerable, a vassal of Hugh Capet. Hugh, with Richard I of Normandy and Fulk Nerra, assembled against him and he had to lift his siege.

Near 995, he entered into a war against Fulk, who was already at war with Geoffrey I of Brittany. Odo allied with his brother-in-law William IV of Aquitaine and Baldwin IV of Flanders. Even his old enemy, Richard of Normandy joined in the war on Fulk. In the winter of 995 – 996, they besieged Langeais, however Odo became ill and was taken to the monastery of Marmoutier at Tours where he died on 12 March 996.

He married (c. 983) Bertha of Burgundy, daughter of King Conrad of Burgundy and Matilda of France. Their children were:

• Robert (died between 980 and 996)
• Theobald II (c. 985–1004)
• Odo II (c. 990–1037)
• Thierry (died 996)
• Agnes, married Viscount Guy of Thouars
• Roger