- Correspondence (Cyprian, Saint, Bishop of Carthage)1
- Cosimo II, Grand Duke of Tuscany, 1590-16211
- Cosimo III, Grand-Duke of Tuscany, 1642-17231
- Cosmography1
- Cosmology1
- Courts and courtiers1
- Covoni, Luigi de1
- Criminal law1
- Cristofano, Filippo di1
- Criticism, Textual1
- Crusades (Fifth) (1218-1221)1
- Cults1
- Dal Borgo family1
- Davanzati, Niccolò1
- De consolatione philosophiae (Boethius)1
- De finibus bonorum et malorum (Cicero, Marcus Tullius)1
- Death1
- Death--Religious aspects--Catholic Church1
- Debt1
- Decedents' estates1