- Masses, Unaccompanied1
- Mathematics, Greek1
- Maurice, Saint, -approximately 2871
- Maximian, Emperor of Rome, approximately 240-3101
- Medea, consort of Aegeus, King of Athens (Mythological character)1
- Medical astrology1
- Medici, Alamanno de'1
- Medici, Bernardo de'1
- Medici, Lorenzo de', 1449-14921
- Medici, Niccolò de'1
- Medicinal plants1
- Medicine, Persian1
- Meditations1
- Mediterranean Region1
- Memory1
- Mercy1
- Metaphysics (Aristotle)1
- Meteorologica (Aristotle)1
- Middle East--Latin Orient1
- Military art and science1