- 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
- Alfonso X, King of Castile and Leon, 1221-12841
- Allegories1
- Annals and chronicles1
- Annotations1
- Anthologies1
- Arithmetic1
- Assassination1
- Astronomy1
- Aubigné, Agrippa d', 1552-16301
- Augustine, of Hippo, Saint, 354-4301
- Autobiographies1
- Batista de Lanuza y Tafalla, Miguel, -1659. Vida de la venerable Madre Geronima de San Estevan1
- Batista de Lanuza y Tafalla, Miguel, -1659. Vida de la venerable madre Feliciana de San Ioseph1
- Battle of Covadonga (Covadonga, Spain : 718)1
- Beards1
- Benefices, Ecclesiastical1