Marius, Aventicus a Swiss prelate, was born of a noble French family of Autun, near the middle of the 6th century. From childhood he was destined for the Church, and his literary remains furnish evidence that he received a careful training. He was made bishop of Aventicum, now Avenches, in the canton Waadt, in 573, or, as some state, in 580. The times were tumultuous, the population depleted, the country impoverished. In these circumstances he distinguished himself by a praiseworthy frugality, and a devotion to agricultural pursuits that furnished the means for a lavish liberality. He was bounteous to the poor, and generous to the Church. In honor of Mary θεοτόκος, he rebuilt the town of Payerne (Paterniacum) on his own lands, and dedicated its church to her; he also donated to this church many of his adjoining lands, on condition, however, that the chapter of Lausanne should derive its tithes from Payerne and two neighboring towns. In the specific work of the episcopal office he was tireless model ecclesiastic for the times. Serving his God with reverence and in humility, he was an impartial judge, a protector of the oppressed, and a devoted shepherd to his flock. Towards the close of his life he translated his see to Lausanne, which from that time gave its name to the diocese. The only additional fact connected with his life that has come to our knowledge is that he was present at the Synod of Macon in 585, which was convened by Guntram, a son of Chlotar, to attempt the purification of the Church in his dominions by executing justice on unworthy members of the clergy. Marius is supposed to have died in 593, and was commemorated at first on the 31st of December, but now on the 4th of February. His Annals, a continuation of the work of Prosper Aquit., are the only writings of his that have reached our time which may justly be ascribed to him. They were published at Paris, in the collections of Du Chesne and Dom Bouquet; at Venice, in the Bibliotheca veter. patruma; and, the best manual, by Rickly, in the Memoires et documens publics par la societe d'histoire de la Suisse Romansde, ton. 13:See Zurlauben, Memoire sur Marius, in the Meims. de I'A cad. roy. des inscript. (Paris, 1770); Herzog, Real-Encyklcop. 9:108 sq.; Wetzer und Welte, Kirchen-Lexikon, 6:891.