Former Owner
- Marie-François Duchesne de Beaumanoir1
- Mary Lacaita1
- Mathias Schurer1
- Matteo Luigi Canonici1
- Matthias Corvinus1
- Maurilio Morazio1
- Menaḥem Naḥum, ha-Leṿi, mi-ḳ.ḳ. Dribin1
- Meschatin La Faye family1
- Michael Wodhull1
- Michiel family1
- Mikhail Golitsyn1
- Millard Meiss1
- Molin1
- Monasterium sanctorum quadraginta martyrum (Treviso Italy)1
- Murray Anthony Potter1
- Nettie Goldsmith Naumburg1
- Niccolò Albergati1
- Nicolai Briganti1
- Nicolas Antoine Labbey de Billy1
- Nicolaus de Monte Murro1