Theodoric I, Count of Montbéliard

Theodoric I (c. 1045 – 2 January 1105) was a count of Montbéliard, Bar, and Verdun and lord of Mousson. He was the son of Count Louis of Montbéliard and Countess Sophie of Bar.

After his father's death, he claimed the estate of the Duchy of Lorraine, which his father had already claimed. 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. Reconciled with the Church, he founded an abbey in 1074 in Haguenau and rebuilt the church at Montbéliard in 1080. He did not participate at the Council of Clermont in 1095, or the Crusades, but rather sent his son Louis in the Crusades. In 1100, the bishop of Verdun gave the county to Thierry for life, but the relationship between the spiritual and temporal powers was turbulent.

In 1065 Theodoric married Ermentrude (1055–1105), daughter of Count William I of Burgundy. They had:

Theodoric II (1081–1163), Count of Montbéliard Louis, who became a crusader, returned in 1102 and was assassinated in 1103 Frederick I († 1160), Count of Ferrette and Altkirch Reginald I (1090–1150), Count of Bar and lord of Mousson Stephen (†1162), bishop of Metz William, who died before 1105 Hugh, cited in 1105, probably religious, because he did not share his father's possessions Gunthilde (†1131), abbess of Biblisheim Agnes, married in 1104 (†1136)