- Margarita, de Austria, Queen, consort of Philip III, King of Spain, 1584-16111
- Marginalia1
- Marriage (Canon law)1
- Marriage (Canon law)--Dispensations1
- Marshals1
- Mary, of Bethany, Saint1
- Mass1
- Materia medica, Vegetable1
- Mathematics3
- Mayenne, Charles de Lorraine, Duc de, 1554-16111
- Medicinal plants1
- Medicine2
- Medicine, Medieval2
- Medina Sidonia, Alonso Pérez de Guzmán, duque de, 1550-16191
- Medina Sidonia, Juan Alonso de Guzmán, Duque de, -15581
- Medina, Francisco de, 1544-16151
- Mediterranean Sea1
- Military policy2
- Missals2
- Missals (Service books)1