- Luke, Saint1
- Lumbres, Ernulfus de1
- Magistrates, Roman1
- Magna Carta1
- Maimonides, Moses, 1135-12041
- Majolus, Saint, Abbot of Cluny, approximately 906-9941
- Mandeville, John, Sir1
- Manichaeism1
- Manners and customs1
- Manuscripts1
- Margaret, Queen, consort of James IV, King of Scotland, 1489-15411
- Margaret, of Antioch, Saint1
- Marina, Saint1
- Marriage1
- Marriage (Canon law)1
- Marriage--Moral and ethical aspects1
- Mary Magdalene, Saint1
- Mary, Blessed Virgin, Saint, in the liturgy1
- Mass--Celebration1
- Matthias I, King of Hungary, 1443-14901