Former Owner
- Comte André de Riaucourt1
- Conradus Eerens1
- Convent San Marco1
- Coppo family1
- Cordwainer Smith1
- Cornelius John Hauck1
- Cortlandt F. Bishop1
- Cosimo de' Medici1
- Count Alexis de Golowkin1
- Count Johann Nepomuk Wilczek1
- Couvent des Minimes (Clermont-Tonnerre, France)1
- Cover of a binding, illegible on what was the outer side.1
- Cox Macro1
- Cristoferus Chrewczer1
- Curt H. Reisinger1
- D'Assonleville family1
- D. Andreas Parisino1
- D. Justin McCann1
- Daniel Itzig1
- David Bickersteth Magee1