- Boethius, -5241
- Botany, Medical1
- Bouchard family1
- Bourbon, Jacques de, 1370-14381
- Bowyer, William1
- Bracciolini, Poggio, 1380-14591
- Breviary (Catholic Church)1
- Brutus, the Trojan (Legendary character)1
- Bulls, Papal1
- Camaldolese1
- Campoy family1
- Cardinal virtues1
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- Cathedral bindings1
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- Catholic Church. Archdeaconry of London (England)1
- Catholic Church. Collectarium1
- Catholic Church. Diocese of Salisbury (England)1
- Catholic Church. Diocese of Sigüenza-Guadalajara (Spain)1
- Catholic Church. Ordo divini officii (Archdiocese of Mainz : Rhineland-Palatinate, Germany)1