- Maurice, Saint, -approximately 2871
- Maximus, of Turin, Saint, active 4th century-5th century1
- Mechanics1
- Medea, consort of Aegeus, King of Athens (Mythological character)1
- Medicine, Greek and Roman1
- Medicine, Greek and Roman--Manuscripts1
- Medicine, Magic, mystic, and spagiric1
- Medicine, Persian1
- Mediterranean Region1
- Mediterranean Sea1
- Merchants1
- Merlin (Legendary character)1
- Meschiati, Giovanni1
- Metaphysics (Aristotle)1
- Mezuzah1
- Middle East--Jerusalem1
- Middle East--Palestine1
- Military history, Medieval1
- Military orders1
- Mills and mill-work1