Former Owner
- Justin MacCarthy Reagh1
- Karl F. Morrison1
- Katharinenkirche, Nuremberg1
- Katholieke Universiteit te Leuven Universiteitsbibliotheek1
- Kenneth Hyde1
- Kloster Bredelar1
- Kulturhistorisches Museum Magdeburg1
- Lady Margaret Ayloffe1
- Lajos Graf Apponyi de Nagy-Appony1
- Lambertus Eerens1
- Lancino Curti1
- Latham family1
- Laura Hurd Motion1
- Laurence William Hodson1
- Laurentius van der Torqel1
- Law Society1
- Leonard Grey, 1st Viscount Grane1
- Leonardo Lapiccirella1
- Leopold Gruber1
- Libreria la Bibliofila1