- Crucifixion of Jesus Christ1
- Crusades (Fifth) (1218-1221)1
- Cryptography1
- Cueva y de Castilla, Beltrán III de la, Duke of Alburquerque, -16121
- Cueva, Andrea della1
- Customary law1
- Customs administration1
- Cynics (Greek philosophy)1
- Dal Borgo family1
- Dance of death1
- Dati, Agostino, 1420-14781
- Dati, Jacopo1
- Dati, Niccolò, 1458-1500 or 15011
- Davanzati, Niccolò1
- De caelo (Aristotle)1
- De institutione musica (Boethius)1
- De interpretatione (Aristotle)1
- De motu animalium (Aristotle)1
- De mundo (Aristotle)1
- Death1