Former Owner
- Birgittinessenklooster Mariënwater1
- Boies Penrose II1
- Budapest University of Jewish Studies1
- Burg Kreuzenstein1
- Caesareum Societatis Jesu Collegium Viennense1
- Carleton Rubira Richmond1
- Catherine de' Medici1
- Cecil Deedes1
- Charles Edward Harris-St. John1
- Charles Kothen1
- Charles Lormier1
- Charles Seymour, 6th Duke of Somerset1
- Charles Stephen Ascherson1
- Charles-Adrien Picard1
- Chartreuse Saint-Sixte de Rettel1
- Chartreuse de Val-Saint-Esprit1
- Christian Brevoort Zabriskie1
- Christian Friedrich August Günther1
- Clement VII1
- Clemente Carilli1