Former Owner
- City College of New York1
- Clarence Howard Clark, Sr.1
- Claude Joseph Constant Despine1
- Claude Le Muet1
- Claude de Fonsèque1
- Clemente Carilli1
- Collegium Germanicum et Hungaricum1
- Coluccio Salutati1
- 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