- Martinus, Polonus, -12791
- Mary, Blessed Virgin, Saint1
- Mass (Music)1
- Mathematics, Greek1
- Maxims1
- Medici, Lorenzo de', 1449-14921
- Medicine, Ancient1
- Medicine, Medieval1
- Merovingian scripts1
- Metaphysics (Aristotle)1
- Mexico--Chiapas1
- Mexico--Michoacán de Ocampo1
- Michaelmas1
- Michelangelo Buonarroti, 1475-1564. Correspondence1
- Military campaigns1
- Miracles1
- Missions1
- Monasteries1
- Monasterio de San Jerónimo de Monte Olivete (Sant Pere de Ribes, Spain)1
- Monasterio de San Jerónimo de la Murtra (Badalona, Spain)1