Theuderic I was the Merovingian king of Metz, Rheims, or Austrasia - as it is variously called - from 511 to 533 or 534.
He was the son of Clovis I and one of his earlier wives or concubines (possibly a Franco-Rhenish Princess, Evochildis of Cologne). He inherited Metz in 511 at his father's death. In accordance with Salian tradition, the kingdom was divided between Clovis's four surviving sons: Childebert I in Paris, Chlodomer in Orléans, and Clotaire I in Soissons. Early in his reign, he sent his son Theudebert to kill the Scandinavian King Chlochilaich (Hygelac of Beowulf fame) who had invaded his realm.
Theuderic got involved in the war between the Thuringian King Hermanfrid and his brother Baderic. Theuderic was promised half of Thuringia for his help; Baderic was defeated, but the land promised was not given up.
The four sons of Clovis then all fought the Burgundian kings Sigismund and Godomar; Godomar fled and Sigismund was taken prisoner by Chlodomer. Theuderic married Sigismund's daughter Suavegotha. Godomar rallied the Burgundian army and won back his kingdom. Chlodomer, aided by Theuderic, defeated Godomar, but died in the fighting at Vézeronce.
Theuderic then, with his brother Clotaire and his son, attacked Thuringia to revenge himself on Hermanfrid. Thuringia was conquered, and Clotaire received Radegund, daughter of King Berthar (Hermanfrid's late brother). After making a treaty with his brother Childebert, Theuderic died in 534. Upon his death the throne of Metz, passed (without hindrance, unexpectedly) to Theudebert. Theuderic also left a daughter Theodechild (by his wife Suavegotha, daughter of the defeated Sigismund of Burgundy). Theodechild founded the Abbey of St-Pierre le Vif at Sens.