Theodoric I (French: Thierry) (ca.
He was the son of Louis, Count of Montbéliard, and Sophie, Countess of Bar and Lady of Mousson.
The claim was dismissed by Emperor Henry IV, confirming the duchy to Theodoric the Valiant.
In retaliation, he ravaged the diocese of Metz, but he was defeated by Adalbéron III, bishop of Metz, and the Duke of Lorraine Theodoric the Valiant.
In 1100, the Bishop of Verdun gave the county to Thierry for life, but the relationship between the spiritual and temporal powers was turbulent.