Former Owner
- Bertram Dobell1
- Betty Freudenheim1
- Beverly Chew2
- Bibliotheca Philosophica Hermetica1
- Brayton C. Ives4
- Bridgewater Library1
- Bristol Baptist College1
- Burndy Library3
- Bury St Edmunds Abbey2
- Carl Reinhardt4
- Carlo Archinto, 2nd Marquess of Parona, 3rd Count of Trainate1
- Carlos José Gutiérrez de los Ríos y Rohan Chabot Fernán-Núñez1
- Caxton Club1
- Charles Butler2
- Charles F. Gunther2
- Charles Stuart, 1st Baron Stuart de Rothesay1
- Charles Thomas-Stanford1
- Charles William Dyson Perrins5
- Charles William Hamilton Sotheby2
- Charles Étienne Brasseur de Bourbourg3