- Calendar reform1
- Calendar, Gregorian1
- Calendars1
- Cambrai, League of, 15081
- Camporitondo, Bartolomeo1
- Cangiano, Giovanni Andrea1
- Canon law1
- Capponi, Ludovico, 1533-16141
- Cardinals--Biography1
- Carli, Giovanfrancesco de'1
- Carlo, Giovanbattista di1
- Categoriae (Aristotle)1
- Catherine, of Alexandria, Saint1
- Catholic Church. Archdiocese of Wrocław (Poland)1
- Catholic Church. Diocese of Cortona (Italy)1
- Catholic Church. Diocese of Pistoia (Italy)1
- Catholic Church. Diocese of Sion (Switzerland)1
- Catholic authors1
- Celleri, Azzo1
- Celleri, Fabrizio1