 When Remaclus retired to Stavelot in 663, Theodard succeeded him as bishop of Maastricht.His biographers describe him as a cheerful and likeable person who performed his role as bishop with great energy and pastoral care.As bishop, in 664 he presided over the dedication of Trudo's abbey (Saint-Trond) to St. Quentin and St. Remigius of Reims.