EUSTASIUS, yu-stê'shi-us . Second abbot of Luxeuil; d. 629. He was of noble family, nephew of Bishop Mietius of Langres, and as discipulus et minister stood in close connection with Columban himself after being received into the monastery at Luxeuil. After Columban had been driven from Luxeuil, Eustasius aided him in his missionary activity by Lake Constance (see COLUMBAN). It is possible that Columban appointed him his successor in the restored mother cloister. At any rate Eustasius was abbot there from 614 with the sanction of King Clothair II. and had supervision over the monasteries connected with Luxeuil. According to the representation of his biographer, who knew him personally, Eustasius was a learned, eloquent, and active man. The bishops Donatus of Besançon, Aichar of Tournai, Chagnoald of Laon, Ragnachar of Basel, the abbots Amatus of Remiremont, Waldebert of Luxeuil, Agilus of Resbais, and the abbess Burgundofara of Faremoutier were his pupils; St. Salaberga was won by him for the spiritual life. He changed nothing in the order of Columban and zealously followed the penitential regulations of the latter (see COLUMBAN). He retained the Irish form of the mass, the tonsure, and daily discipline, as may be seen from the charges made against him by Agrestius (Vita Columbani, ii. 9), but as the Irish celebration of Easter disappears from the charges, it is probable that he ultimately abandoned it. Eustasius also labored for the conversion of heretical and heathen natives; he succeeded in making the Wariskians, dwelling on both sides of the middle Doubs, who followed Bonosus (q.v.), adherents of the Catholic Church. With Agilus he undertook a missionary journey to the Bavarians, but met with slight success. His anniversary is given by Jonas as Apr. 29, but in the Martyrologium Hieronymianum (ASB, Nov., ii. 38) as Apr. 2.