Former Owner
- Ludovico Settala1
- Luigi Celotti1
- Lyon Cathedral1
- M. Haimmiller1
- Malvezzi de' Medici1
- Marienstiftsgymnasium1
- Mario Maffei1
- Mary Augusta Strachey1
- Mary Schell Collins1
- Matteo Barresi1
- Matteo Luigi Canonici1
- Melk Abbey1
- Michel Chasles1
- Michel de Léon1
- Monasterio de El Paular1
- Nicolas Antoine Labbey de Billy1
- Nicolas Fowle1
- Otto Ege1
- Otto Jahn1
- Otto Orren Fisher1