Maassen, Friedrich Bernard Christian
Mabillon, Jean
Macarius 
MacCarthy, Bartholomew 
McCarthy, Justin 
MacCarthy, Nicholas Tuite
Mace
Macedo, Francisco
McSherry, James Sr.
McSherry, James Jr.
McSherry, Richard
Maderna, Carlo
Maderno, Stefano
Madianites
Madras
Madura Mission
Maedoc, Saint
Maelruan, Saint
Maelrubha, Saint
Maerlant, Jacob van
Maestro di Camera del Papa
Maffei, Bernardino
Maffei, Francesco
Maffei, Raffaelo
Magaud, Antoine-Dominique
Magdala
Magdalens
Mageddo
Magellan, Ferdinand
Magi
Magin Catalá
Maginn, Edward
Magistris, Simone de
Magliabechi, Antonio
Magna Carta
Magnificat
Magnus, Saint
Magnus, Olaus
Magnus, Valerianus
Magrath, John Macrory
Magydus
Mahony, Ven. Charles
Maignan, Emmanuel
Mailla, Joseph-Anna-Marie de Moyria de
Maillard, Antoine-Simon
Maillard, Oliver
Maimbourg, Louis
Maimonides, Teaching of Moses
Maintenon, Françoise, Marquise de
Maisonneuve, Paul de Chomedey de
Maistre, Joseph-Marie, Comte de
Maistre, Xavier de
Majano, Benedetto da
Majordomo
Majority
Majunke, Paul
Malabar
Malabar Rites
Malachias
Malachy, Saint
Malagrida, Gabriel
Malchus
Maldonado, Juan
Malebranche, Nicolas
Malediction (in Scripture)
Malherbe, François
Maliseet Indians
Mallard, Ernest-François
Malling Abbey
Manitoba
Mann, Theodore Augustine
Manna
Mannyng, Robert
Mansard, François
Mansard, Jules
Mansi, Gian Domenico
Mantegna, Andrea
Mantelletta
Manu, The Laws of
Manuel Chysoloras
Manuscripts
Manuscripts, Illuminated
Manuscripts of the Bible
Manuterge
Manutius, Aldus
Manzoni, Alessandro
Map, Walter
Maphrian
Maran, Prudentius
Marash
Maratta, Carlo
Marbodius
Marca, Pierre de
Marcellina, Saint
Marcellinus, Pope
Marcellinus Comes
Marcellinus of Civezza, O.F.M.
Marcello, Benedetto
Marcellus of Ancyra
March, Auzias
Marchand, Jean Baptiste
Marchant, Peter
Marciane
Marcianopolis
Marcionites
Marcosians
Marcoux, Joseph
Marcus
Marcus Diadochus
Marcus Eremita
Marenzio, Luca Margaret, Saint
Margaret of Hungary, Blessed
Margaret Colona, Blessed
Margaret of Cortona, Saint
Margaret of Lorraine, Blessed
Margaret of Scotland, Saint
Margaret Pole, Blessed
Marian Priests
Maria Theresa
Marie Antoinette
Marie Christine of Savoy, Blessed
Marie de France 
Marie de l'Incarnation, Blessed
Marie de l'Incarnation, Ven.
Marignolli, Giovanni de
Marinus II, Pope
Mariotte, Edme
Marius Maximus, Lucius Perpetuus Aurelianus
Marius Mercator
Mark, Saint
Mark, Pope Saint
Mark, Gospel of
Mark and Marcellian, Saints
Mark of Lisbon
Maroni, Paul
Maronia
Maronites
Marquette, Jacques
Marquette League
Marriage, Civil
Marriage, History of
Marriage, Mixed
Marriage, Moral and Canonical Aspect
Marriage, Mystical
Marriage, Sacrament of
Marryat, Florence
Marshall, Thomas William
Marshall Islands
Marsi
Marsico Nuovo and Potenza
Marsigli, Luigi Ferdinando, Count de
Martha, Saint
Martin I, Pope St.
Martin IV, Pope
Martín, Enrico
Martina, Saint
Martini, Antonio
Martini, Martino
Martini, Simone
Martinique
Mason, Richard Angelus a S. Francisco
Masonry
Maspha
Massa Marittima
Mass, Chapter and Conventual
Mass, Liturgy of the
Mass, Music of the
Mass, Nuptial
Mass, Sacrifice of the
Massa Candida
Massachusetts
Massé, Enemond
Masses, Bequests for
Massorah
Massoulié, Antoine
Massuet, René
Master of the Sacred Palace
Mastrius, Bartholomew
Mater
Materialism
Maternity of the Blessed Virgin Mary, Feast of
Mathathias
Mathew, Theobald
Mathieu, François-Désiré
Mathusala
Matilda, Saint 
Matilda of Canossa
Matins
Matricula
Matteo da Siena
Matteo di Termini
Matter
Matteucci, Carlo
Matthew, Saint
Matthew, Gospel of Saint
Matthew, Sir Tobie
Matthew of Cracow
Matthias, Saint
Matthias Corvinus
Matthias of Neuburg
Maundy Thursday
Maunoury, Auguste-François
Maurice, Saint 
Maurice
Maurists, The
Maurus, Saint
Maurus, Sylvester
Maxentius, Marcus Aurelius
Maxfield, Venerable Thomas
Maximianopolis
Maximianus
Maximilian 
Maximilian I
Maximinus, Saint, Bishop 
Maximinus, Caius Valerius Daja
Maximinus Thrax
Maximopolis
Maximus of Constantinople, Saint
Maximus of Turin, Saint
Maxwell, William
Maxwell, Winifred
Maya Indians
Mayer, Christian
Mayhew, Edward
Mayne, Blessed Cuthbert
Maynooth College
Mayo, School of
Mazarin, Jules
Mazenod, Charles Joseph Eugene de
Mazzolini, Sylvester 
Meagher, Thomas Francis 
Meath
Meaux, Diocese of
Meaux -- English Cistercian abbey
Mecca
Mechanism
Mechitar
Mechlin
Mechtel, Johann
Mechtilde, Saint -- Benedictine
Medaille, Jean Paul
Medals, Devotional
Medal, Miraculous
Medardus, Saint -- Bishop of Noyon
Medellín
Media and Medes
Mediator (Christ as Mediator)
Medici, House of
Medici, Maria de'
Medicine, History of
Medicine and Canon Law
Medina, Juan de
Medina, Miguel de
Megarians
Mège, Antoine-Joseph
Melancthon, Philipp
Melania (the Younger), Saint
Melchisedech
Melchisedechians
Melchites
Meletius of Antioch
Meletius of Lycopolis
Melito, Saint
Mellitus, Saint
Memling, Hans
Memory
Memphis
Menaion
Menas, Saint
Mencius
Mendaña de Neyra, Alvaro de
Mendel, Mendelism
Méndez and Gualaquiza 
Mendicant Friars
Menéndez y Pelayo, Marcelino
Menestrier, Claude-François
Mennonites
Men of Understanding
Menologium
Mensa, Mensal Revenue
Mental Reservation
Mercedarians
Mercier, Louis-Honoré
Mercuriali, Geronimo
Mercy, Brothers of Our Lady of
Mercy, Corporal and Spiritual Works of
Mérida -- Diocese in Venezuela
Merit
Mermillod, Gaspard
Merneptah I
Mersenne, Marin
Mesa
Messalians
Messiah
Metalwork in the Service of the Church
Metaphrastes, Symeon
Metaphysics
Metempsychosis
Methodism
Methodius of Olympus, Saint
Metropolitan
Meun, Jean Clopinel de
Mexico, Archdiocese of
Miami Indians
Michael the Archangel, Saint
Michael, Military Orders of Saint
Michael Cærularius
Michael de Sanctis, Saint
Michaud, Joseph-François
Micheas of Ephraim
Micheas, Son of Jemla
Micheas, Book
Michelians
Michigan
Micrologus
Middendorp, Jakob
Middle Ages
Midrashim
Midwives
Migazzi, Christoph Anton
Migne, Jacques-Paul
Military Orders, The
Milner, Venerable Ralph
Milo Crispin
Miltiades, Pope Saint
Miltiz, Karl von
Mino di Giovanni
Mirandola, Giovanni Pico
Miridite, Abbey
Miserere
Misericorde, Congregation of the Sisters
Misocco and Galanca
Missal
Mission, Congregation of Priests of the
Missions, Catholic Parochial
Mithraism
Mitre
Mivart, St. George Jackson
Moab, Moabites
Modernism
Mohammed and Mohammedism
Moigno, François-Napoléon-Marie
Molai, Jacques de
Molesme, Notre-Dame de
Molina, Juan Ignacio
Molina, Luis de
Molinism
Molinos, Miguel de
Moloch
Monaco, Principality and Diocese of
Monad
Monarchians
Monasteries, Double
Monasteries in Continental Europe, Suppression
Monasteries in England, Suppression
Monastery, Canonical Erection of a
Monasticism
Monasticism, Eastern
Monasticism, Pre-Chalcedonian
Monasticism, Western
Mondino dei Lucci
Monica, Saint
Monism
Monita Secreta
Monk
Monogram of Christ
Monophysites and Monophysitism
Monopoli, Diocese of
Monopoly, Moral Aspects of
Monothelitism and Monothelites
Monreale
Monroe, James
Monseigneur
Monsell, William, Baron Emly
Monsignor
Montaigne, Michel-Eyquen de
Montana
Montanists
Montboissier, Blessed Peter of
Montesa, Military Order of
Montesinos, Luis de
Montes Pietatis
Montesqieu, Charles-Louis de Secondat, Baron
Monte Vergine
Montgolfier, Joseph-Michel
Months, Special Devotions for
Montreal, Archdiocese of
Mont-St-Michel
Montyon, Antoine-Jean-Baptiste-Robert Auget, Baron
Morales, Christóbal
Morales, Luis de
Moralities
Morality
Moravia
Morcelli, Stefano Antonio
More, Helen 
More, Henry 
Morgagni, Giovanni Battista
Morgan, Venerable Edward
Mormons
Morris, John
Morse, Venerable Henry
Mortification
Mortmain
Morton, Ven. Robert
Mosaic Legislation
Mosaics
Moschus, Johannes
Moses
Most Pure Heart of Mary, Feast of
Mosynoupolis
Motet
Motolinia, Toribio de Benavente 
Motu Proprio
Mouchy, Antoine de
Mount Calvary, Congregations of
Mount Carmel, Feast of Our Lady of
Moye, Ven. John Martin
Mozambique
Mozarabic Rite
Mozart, Wolfgang Amadeus 
Mozetena Indians
Mozzetta
Mozzi, Luigi
Müller, Johann
Müller, Karl
Munkács
Mura, Saint
Muratorian Canon
Murillo, Bartolomé Esteban
Murray, John O'Kane
Musical Instruments in Church Services
Mutis, José Celestino
Muzzarelli, Alfonso
Mylasa
Myra
Myrina
Myriophytum
Mystery
Mystical Body of the Church
Mysticism