- Alchemy--Manuscripts1
- Aleramo, Marquis of Monferrato, -9671
- Alexander III, Pope, -11811
- Alexander VII, Pope, 1599-16671
- Alfonso II, King of Naples, 1448-14951
- Alfonso V, King of Aragon, 1396-14581
- Algebra1
- Alliata family1
- Almanach perpetuum celestium motuum (Zacuto, Abraham ben Samuel)1
- Altoviti, Bartolomea1
- Amadori, Bartolomeo1
- Amadori, Lorenzo1
- Amadori, Niccolo1
- Angelio family1
- Angels1
- Angèli, Pietro, 1517-15961
- Antidotes1
- Antiquities1
- Apocryphal and legendary literature1
- Apologetics1