Former Owner
- Louis II, Count of Flanders1
- Lucien Magne1
- Léon Gruel1
- Léon Techener1
- Marcela Gabriela1
- Margaret F. Woodward1
- Marguerite de Fontenay1
- Marie Ange-Toussaint Placide de Ferron1
- Marie Cleophe de Sollario1
- Marie de Albano1
- Mariota Lyle1
- Martinus Nijhoff1
- Maurice Kann1
- Mayfair Rare Books and Manuscripts1
- Middle Hill Rare Books & Manuscripts AB (Stockholm, Sweden)1
- Minerva Kaiser1
- Minnis, Katherine1
- Monsieur de Bel Air1
- Mrs. F. W. Bartlett1
- Muriel Agnes Fry1