Former Owner
- Claude Augustin de Cosson1
- Claude Joseph Constant Despine1
- Clemente Carilli1
- Cloître de la Chartreuse du Val de Bénédiction1
- Collegium Germanicum et Hungaricum1
- Cologne Charterhouse1
- Coluccio Salutati1
- Cornelius John Hauck1
- Cortlandt F. Bishop1
- Cristoferus Chrewczer1
- D. Andreas Parisino1
- Dawson Turner1
- Dean Putnam Lockwood1
- Dionysiĭ Vasilevich1
- Donaueschingen court library1
- Duncan Beresford-Jones1
- Edmond Révérend du Mesnil1
- Edmund Newman1
- Edward Cheney1
- Edward Samuel Dewick1