Former Owner
- Coluccio Salutati1
- Comte Chandon de Briailles1
- Comte d'Aspremont-Lynden1
- Condat Abbey1
- Constance de Foix1
- Convent San Marco1
- Convent of San Domenico1
- Convento di San Paolo1
- Coppo family1
- Cordwainer Smith1
- Cornelius John Hauck1
- Corp. Thomas Tay1
- Cosimo de' Medici1
- Count Alexis de Golowkin1
- Count Johann Nepomuk Wilczek1
- Couvent des pères Franciscains (Monte-Carlo, Monaco)1
- Cristoferus Chrewczer1
- Curt H. Reisinger1
- D'Assonleville family1
- D. D. Horatius Bosner1