- Revolutions1
- Rhetoric1
- Ripley, George, -1490?1
- Roger, of St. Albans1
- Romances, Spanish1
- Rome (Empire)1
- Rueda family1
- Rueda, Baltasar de, active 1553-15691
- Rueda, Bernardino de, active 1553-15691
- Rueda, Luis de, active 1553-15691
- Rueda, Rodrigo de, active 1553-15691
- Rufina, Saint, -approximately 2871
- Rules1
- Sacraments--Catholic Church1
- Sacred books1
- Salt mines and mining1
- Sancho Garcés I, King of Navarre, -9251
- Sancho IV, King of Castile and Leon, 1257-12951
- Savelli, Troilo, -15921
- Science1