Former Owner
- Bernard Rosenthal1
- Bernardi1
- Bernardo Mendel1
- Bibliotheca Philosophica Hermetica1
- Boies Penrose II1
- Bonvesino, Marco1
- Bridget Hunt1
- Budapest University of Jewish Studies1
- Burg Kreuzenstein1
- Burndy Library1
- Camillo Riccio1
- Carleton Rubira Richmond1
- Carlo Archinto, 2nd Marquess of Parona, 3rd Count of Trainate1
- Carlo Morbio1
- Cecil Deedes1
- Charles Augustus Stoddard1
- Charles Edwin Puckett1
- Charles F. Gunther1
- Charles Fairfax Murray1
- Charles Stephen Ascherson1