- Artedo, Petrus de1
- Arthur, King1
- Artillery1
- Astrology, Arab1
- Astrology, Roman1
- Astronomical instruments1
- Atlantic Ocean--English Channel1
- Aubertus, de Galardone1
- Averroës, 1126-1198. Talkhīs kitāb al-ʻIbārah1
- Averroës, 1126-1198. Talkhīṣ kitāb al-maqūlāt1
- Averroës, 1126-1198. Talkhīṣ madkhal Furfūriyūs1
- Balances (Weighing instruments)1
- Ballads1
- Baptism1
- Baptism of Jesus Christ1
- Barberino, Bardo da1
- Bartholomeo, de Soncino1
- Bartholomew, of San Concordio, 1262-13471
- Bassianus, of Glisate1
- Battle of Pharsalus (Farsala, Greece : 48 B.C.)1