Former Owner
- Bridgewater Library1
- Carlos José Gutiérrez de los Ríos y Rohan Chabot Fernán-Núñez1
- Caxton Club1
- Charles Butler1
- 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
- Claude d'Urfé1
- Coggeshall Abbey1
- Couvent des pères Franciscains (Monte-Carlo, Monaco)1
- Dahīʹzādah1
- Dame Margery Byrkenhed1
- Darvīsh Aḥmad Khākiyānī1
- Dawson Turner1
- Diego Clemencín1
- Diego Llorente1
- Diego de Arce y Reinoso1