- Confession--Catholic Church--Handbooks, manuals, etc--Early works to 18005
- Confessors1
- Confraternities4
- Conic sections1
- Conics (Apollonius, of Perga)1
- Conscience, Examination of1
- Consolation4
- Constantine XI Palaeologus, Emperor of the East, 1405-14531
- Constitutions1
- Construction industry1
- Controlled vocabularies2
- Controversial literature2
- Cooking1
- Cooking, English1
- Coptic manuscripts1
- Corsini, Bartolomeo1
- Cosimo I, Grand-Duke of Tuscany, 1519-15742
- Cosmography4
- Cosmology3
- Council of Basel2