- Jiménez de Cisneros, Francisco, 1436?-15171
- John II, King of Aragon, 1397-14791
- Juana, of Austria, Princess of Portugal, 1535-15731
- Knights of Malta1
- Laudatory poetry, Latin1
- Lawyers1
- Legal documents1
- Lemos, Pedro Fernández Ruiz de Castro y Osorio, conde de, active 17th century1
- Lyric poetry1
- Manuscripts, Arabic1
- Manuscripts, French1
- Manuscripts, Galician1
- Manuscripts, German1
- Manuscripts, Renaissance1
- Margarita, de Austria, Queen, consort of Philip III, King of Spain, 1584-16111
- Martyrdom1
- Martyrs1
- Mathematical instruments1
- Medicine1
- Medina Sidonia, Alonso Pérez de Guzmán, duque de, 1550-16191