- Administration2
- Adrian VI, Pope, 1459-15231
- Aegidius, Saint, Abbot1
- Agreda, Dominici d'1
- Agriculture1
- Ajurrūmīyah (Ibn Ājurrūm, Muḥammad ibn Muḥammad)2
- Alban, Saint, -304?1
- Albertus de Fontanella1
- Albigenses1
- Albizzi, Costanza1
- Alchemy13
- Alchemy--Bibliography1
- Alexander III, Pope, -11811
- Alexander, de Villa Dei. Doctrinale puerorum1
- Alexander, the Great, 356 B.C.-323 B.C.6
- Alexius, Saint1
- Alfonso V, King of Aragon, 1396-14581
- Alfonso X, King of Castile and Leon, 1221-12841
- Alfīyah (Ibn Mālik, Muḥammad ibn ʻAbd Allāh)2
- Algebra5