- Concini, Alessandra Antinori1
- Concini, Arrigo1
- Concini, Giovanbattista1
- Constellations1
- Constellations--Names1
- Contemporary bindings1
- Corsini, Bartolomeo1
- Cortesi, Girolamo1
- Cosimo II, Grand Duke of Tuscany, 1590-16211
- Cosimo III, Grand-Duke of Tuscany, 1642-17231
- Cosmography1
- Cosmology, Medieval1
- Dawwānī, Muḥammad ibn Asʻad, 1426 or 1427-1512 or 1513. Risālat ithbāt al-wājib (al-qadīmah)1
- De la Peña family1
- Dervishes1
- Devil--Islam1
- Devotional poetry, Arabic1
- Dhimmis (Islamic law)1
- Didactic poetry, Arabic1
- Divination--Religious aspects--Islam1