Former Owner
- Bernard M. Rosenthal1
- Bernard Serrigny1
- Bernardo Bembo1
- Bertram Dobell1
- Betty Freudenheim1
- Bibliotheca Philosophica Hermetica1
- Bridgewater Library1
- Bristol Baptist College1
- Carlo Archinto, 2nd Marquess of Parona, 3rd Count of Trainate1
- Carlos José Gutiérrez de los Ríos y Rohan Chabot Fernán-Núñez1
- Caxton Club1
- Charles Stuart, 1st Baron Stuart de Rothesay1
- Charles Thomas-Stanford1
- Charles-Gilbert Morel de Vindé1
- Christophorus de Stinglhaim1
- Clara von Vorssel1
- Clarence Howard Clark, Sr.1
- Coggeshall Abbey1
- Couvent des pères Franciscains (Monte-Carlo, Monaco)1
- Dahīʹzādah1