- Medina Sidonia, Juan Alonso de Guzmán, Duque de, -15581
- Medina, Francisco de, 1544-16151
- Meditations1
- Mediterranean Sea1
- Missions1
- Missions, Portuguese1
- Monasteries1
- Monasterio de Santa María (Vallbona de las Monjas, Spain)1
- Monasterio de Villaverde de Sandoval1
- Monastic and religious life1
- Monasticism and religious orders1
- Monasticism and religious orders--Rules1
- Montalvan, Alonso de1
- Montúfar, Alonso de, active 1512-15701
- Municipal government1
- Music1
- Naples (Kingdom)1
- Natural history1
- Natural law1
- Nautical charts1