- Isidore, of Seville, Saint, -6361
- Islam1
- Italy1
- James, the Greater, Saint1
- Jerónima de la Asunción, madre, 1555-16301
- Jesuit drama, Spanish1
- Jesuits1
- Juana, of Austria, Princess of Portugal, 1535-15731
- Latin language--Study and teaching1
- Latin poetry1
- Lawyers1
- Lemos, Pedro Fernández de Castro, conde de, 1576-16221
- Letter of Aristeas1
- León, Luis de, 1527-15911
- Liturgical books1
- Magic1
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- Manuscripts, French1
- Manuscripts, Galician1
- Margarita, de Austria, Queen, consort of Philip III, King of Spain, 1584-16111