Friedrich Bernard Christian Maassen
United Sees of Macerata and Tolentino
Vicariate Apostolic of Mackenzie
Marie-Edmé-Patrice-Maurice de MacMahon
Joseph-Anna-Marie de Moyria de Mailla
François-Pierre-Gonthier Maine de Biran
Françoise, Marquise de Maintenon
Joseph-Marie, Comte de Maistre
Marcellinus of Civezza, O.F.M.
Margaret of the Blessed Sacrament
Prefecture Apostolic of Mariana Islands
Congregation of the Missionaries of Mariannhill
Sts. Maris, Martha, Audifax, and Abachum
Lucius Perpetuus Aurelianus Marius Maximus
Vicariate Apostolic of Marquesas Islands
Moral and Canonical Aspect of Marriage
Diocese of Marseilles (Massilia)
Vicariate Apostolic of the Marshall Islands
Diocese of Marsico Nuovo and Potenza
Luigi Ferdinando, Count de Marsigli
Missionaries of the Company of Mary
Servants of Mary (Order of Servites)
Society of Mary (Marist Fathers)
St. Mary Frances of the Five Wounds of Jesus
Richard Angelus a S. Francisco Mason
Devises and Bequests for Masses (United States)
Feast of the Maternity of the Blessed Virgin Mary
Marcus Aurelius Valerius Maximianus
Caius Julius Verus Maximinus Thrax
Prefecture Apostolic of Mayotte, Nossi-Bé, and Comoro
Charles Joseph Eugene de Mazenod
Abbey and Congregation of Melk
Vicariate Apostolic of Méndez and Gualaquiza
Francisco Sarmiento de Mendoza
Corporal and Spiritual Works of Mercy
Sisters of Mercy of St. Borromeo
Frédéric-François-Xavier Ghislain de Mérode
Delegation Apostolic of Mesopotamia, Kurdistan, and Armenia
Metal-Work in the Service of the Church
Prince Klemens Lothar Wenzel von Metternich
Francis, Joseph, and Paul Mezger
Military Orders of St. Michael
Giovanni Francesco Pico della Mirandola
Congregation of the Sisters of Misericorde
Prefecture Apostolic of Misocco and Calanca
Congregation of Priests of the Mission
Congregation of Missionaries of St. Charles Borromeo
Missionaries of St. Francis de Sales of Annecy
Missionary Society of St. Paul the Apostle
Mission Indians (of California)
Catholic Indian Missions of Canada
Catholic Indian Missions of the United States
François-Napoléon-Marie Moigno
Diocese of Molfetta, Terlizzi, and Giovinazzo
Jean-Baptiste Poquelin Molière
Principality and Diocese of Monaco
Canonical Erection of a Monastery
Monophysites and Monophysitism
Monothelitism and Monothelites
Montagnais Indians (Chippewayans)
Charles-Forbes-René, Comte de Montalembert
Marquis de Louis-Joseph Montcalm-Gozon
Diocese of Monterey and Los Angeles
Charles-Louis de Secondat, Baron de Montesquieu
Anne, First Duke of Montmorency
Alexis-François Artaud de Montor
Antoine-Jean-Baptiste-Robert Auget, Baron de Montyon
Dioceses of Mostar and Markana-Trebinje
Feast of the Most Pure Heart of Mary
Toribio de Benavente Motolinia
Congregations of Mount Calvary
Feast of Our Lady of Mount Carmel
Karl Ernst, Freiherr von Moy de Sons
Johann Chrysostomus Wolfgang Amadeus Mozart
St. Clair Augustine Mulholland
Baron Eligius Franz Joseph von Münch-Bellinghausen
Archdiocese of Munich-Freising
Bishop of Vienne, date of birth unknown; died shortly after 475. Concerning the life of Mamertus before his elevation to the See of Vienne, nothing certain is known. The fact that his brother, Claudianus Mamertus, the theological writer, received in his youth a sound training in rhetoric, and enjoyed the personal acquaintance of Bishop Eucherius of Lyons (434-50), suggests that the brothers belonged to a wealthy Gallic family from the neighbourhood of Lyons. Like his brother, St. Mamertus was distinguished for his knowledge of profane subjects as well as of theology, and, before his elevation to the episcopate, appears to have been married. His election and consecration took place shortly before 462. As bishop he enlisted the services of his brother, who had withdrawn to a cloister, and ordained him priest of Vienne. The activity of the brothers is described in a letter of Sidonius Apollinaris (Epist., IV, xi), another of whose letters (VII, i) is addressed to Bishop Mamertus. In 463 Mamertus was engaged in a dispute with Pope Hilarius on the question of the privileges of the Bishop of Arles. Pope Leo I had regulated the boundaries of the ecclesiastical provinces of Arles and Vienne: under the latter he left the Dioceses of Valence, Tarentaise, Geneva, and Grenoble, but all the other dioceses in this district were made subordinate to Arles. Regardless of this decision and infringing on the rights of his colleague of Arles, Mamertus consecrated in 463 a bishop for the city of Die (Dea). King Gundiac of Burgundy complained to Pope Hilary of this action, whereupon the latter wrote to Bishop Leontius of Arles on 10 Oct., 463, bidding him summon a synod of bishops from the different provinces to enquire into the matter. In a subsequent letter to the bishops of the provinces of Lyons, Vienne, Narbonnensis I and II, and Alpina, he also refers to the matter, and directs them to obey Leontius's summons to a regularly constituted synod (Thiel, "Epist. Rom. Pont.", I, cxlvi, cli; Jaffé, "Regesta Rom. Pont.", I, 2nd ed., dlvi, dlix). The synod decided against Mamertus, as we learn from another letter of the pope dated 25 February, 464 (Thiel, op. cit., I, cxlviii; Jaffé, op. cit., I, dlvii). In this Hilary declares that Mamertus and the bishop unlawfully consecrated by him should really be deposed; desiring, however that clemency be used, he commissioned Bishop Veranus to inform Mamertus that, if he did not recognize and submit to the regulations of Pope Leo, he would be deprived also of the four suffragan dioceses, still subject to Vienne. The bishop invalidly installed by Mamertus was to be confirmed in his office by Leontius, after which he might retain the bishopric. Mamertus evidently submitted, since we find no subsequent reference to the incident.
During his episcopate, the remains of St. Ferreolus were discovered, and were translated by Mamertus to a church in Vienne, built in honour of that holy martyr (Gregory of Tours, "De gloria mart.", II, ii). St. Mamertus was the founder of the Rogation Processions (see ROGATION DAYS), as we learn on the testimony of Sidonius Apollinaris (Epist., V, xiv; VII, i), and his second successor, Avitus ("Homilia de Rogat." in P. L., LIX, 289-94). In connexion with these intercessory processions, Mamertus summoned a synod at Vienne between 471 and 475. About 475 he attended a synod at Arles, which dealt with the predestination teaching of Lucidus, a Gallic priest. As this is the latest information we possess concerning him, we may assume that he died shortly afterwards. After his death he was venerated as a saint. His name stands in the "Martyrologium Hieronymianum" and in the "Martyrologium" of Florus of Lyons under 11 May, on which day his feast is still celebrated (Quentin, "Les martyrologes historiques", 348).
DUCHESNE, Fastes épiscopaux de l'ancienne Gaule, I (Paris, 1894), 147; HEFELE, Konziliengesch., II (2nd ed.), 580 sqq., 596, 597; Acta SS., II. 629 sq.; TILLEMONT, Mémoires pour servir à l'hist. eccl, XVI, 104; TERREBASSE, Notice sur le tombeau de St. Mamert récemment découvert dans l'église de St. Pierre à Vienne (Vienne, 1861).
J.P. KIRSCH