- Mayenne, Charles de Lorraine, Duc de, 1554-16111
- Medicine1
- Medina Sidonia, Alonso Pérez de Guzmán, duque de, 1550-16191
- Medina Sidonia, Juan Alonso de Guzmán, Duque de, -15581
- Medina, Francisco de, 1544-16151
- Meditations1
- Mediterranean Sea1
- Metaphysics (Aristotle)1
- Mexico--Mexico City1
- Missals1
- Missals (Service books)1
- Missions1
- Missions, Portuguese1
- Monasteries1
- Monasterio de Villaverde de Sandoval1
- Monastic and religious life of women1
- Monasticism and religious orders1
- Monasticism and religious orders for women1
- Music1
- Music theory1