Anth - Arca
- Arabian School of Philosophy
- Arabici
- Arabissus
- Arad
- Aragon and Castile
- Aran, The Monastic School of
- Aranda, Council of
- Aranda, Philip
- Arason Jón
- Arator
- Araucania
- Araucanians
- Araujo, Antonio de
- Araujo, Francisco de
- Arawaks
- Arbieto, Ignacio de
- Arbitration
- Arbogast, Saint
- Arbroath, Abbey of
- Arbuthnott, Missal of