Former Owner
- Nasir al-Din al-Tusi1
- Nicolas Antoine Labbey de Billy1
- Otto Vollbehr1
- Owen D. Young1
- Paolo Giovio1
- Pauline Fore Moffitt1
- Paulus de Graecus1
- Phoebe Hearst1
- Pierre Pithou1
- Prediger (Schwäbisch Gmünd)1
- Prince Augustus Frederick, Duke of Sussex1
- Ramsau Monastery1
- Raoul Chandon de Briailles1
- Robert Brodhead Honeyman1
- Robert Hoe III1
- Robert Rossiter Hutton1
- Rudolf Busch1
- Samuel Butler1
- Samuel H. Putnam1
- Seymour Stocker Kirkup1