Around 448 Abundius became the fourth Bishop of Como, succeeding Amantius. The Romanesque church of Sant'Abbondio at Como, consecrated in 1095 by Pope Urban II, is dedicated to him, and his relics are conserved beneath its principal altar. The church has a nave and four aisles and two notable bell towers rising at the end of the external aisles, in the middle of the nave (preceding the apse). It was part of a Benedictine monastery, recently restored.