- Justa, Saint, -approximately 2871
- Knights of Malta1
- Lafões, Pedro Henrique de Bragança, Duque de, 1718-17611
- Law1
- Leocadia, Saint, -3031
- Lorraine, Nicolas-François, duc de, 1609-16701
- Manuel I, King of Portugal, 1469-15211
- Manuscript maps1
- Manuscript waste1
- Manuscripts, Catalan1
- Manzoli, Marchione1
- Maps1
- Maria Anna Josefa, Queen, consort of John V, King of Portugal, 1683-17541
- Marriage (Canon law)1
- Marriage (Canon law)--Dispensations1
- Marshals1
- Mayenne, Charles de Lorraine, Duc de, 1554-16111
- Medical formularies1
- Medici, Alessandro de', 1510-15371
- Medici, House of1