Former Owner
- Charles Stephen Ascherson1
- Chartreuse Saint-Sixte de Rettel1
- Christian Brevoort Zabriskie1
- Christopher Pease, 2nd Baron Wardington1
- Clemente Carilli1
- Collegium Germanicum et Hungaricum1
- Convent San Marco1
- Cornelius John Hauck1
- Cosimo de' Medici1
- Count Johann Nepomuk Wilczek1
- Cristoferus Chrewczer1
- D. Andreas Parisino1
- Daniel Itzig1
- David Solomon Sassoon1
- David Werner Amram1
- Dean Putnam Lockwood1
- Dionysiĭ Vasilevich1
- Domenico Toschi1
- Donaueschingen court library1
- Edmund Newman1