- Asceticism--Early church1
- Asia1
- Astrolabes1
- Astrology, Roman1
- Astronomy, Ancient1
- Astronomy, Arab1
- Astronomy, Greek1
- Augustus, Emperor of Rome, 63 B.C.-14 A.D.1
- Authors, Latin1
- Aveiro, Gabriel de Lencastre, Duque de, 1667-17451
- Azar, Menaḥem ben Natan1
- Bartolo, of Sassoferrato, 1313-13571
- Basil, Saint, Bishop of Caesarea, approximately 329-3791
- Battle of Agincourt (Agincourt, France : 1415)1
- Battle of Pharsalus (Farsala, Greece : 48 B.C.)1
- Beards1
- Belgium--Tournai1
- Benedict, Saint, Abbot of Monte Cassino1
- Benedictine nuns1
- Benedictus Dominus Deus Israel (Music)1