- Alessandri, Alessandro degli1
- Alessandri, Niccolò degli1
- Alessandro, Pietro di1
- Alexander Balas, King of Syria, -145 B.C.1
- Alexander III, Pope, -11811
- Alexander, the Great, 356 B.C.-323 B.C.1
- Alfonso I King of Asturias, 693-7561
- Alfonso III, King of Asturias and Leon, approximately 848-approximately 9101
- Alfonso V, King of Aragon, 1396-14581
- Alfonso V, King of Asturias and León, 994-1027 or 10281
- Alfonso VI, King of Castile and Leon, 1030-11091
- Alfonso VII, The Emperor, King of Castile, 1104-11571
- Alfonso VIII, King of Castile, 1155-12141
- Alliata family1
- Almucantar1
- Alvarez family1
- Amadori family1
- Amadori, Francesco1
- Amadori, Lorenzo1
- Ambrogio, Leonardo d'1