Dukes | Titles by Rank
- Dukes of Casigliano
- Dukes of Casoli
- Dukes of Cassano
- Dukes of Castel Airol
- Dukes of Castel Duino
- Dukes of Castel Sangro
- Dukes of Castel Vecchio
- Dukes of Castelchiodato
- Dukes of Castelluccio
- Dukes of Castelluccio
- Dukes of Castelvari e di Zoagli
- Dukes of Castelvaro
- Dukes of Castries
- Dukes of Castro
- Dukes of Castro Enriquez
- Dukes of Castro Terreño
- Dukes of Castrovillari
- Dukes of Caumont
- Dukes of Caxias
- Dukes of Caylus
- Dukes of Cea
- Dukes of Celenza
- Dukes of Cercemaggiore
- Dukes of Ceri
- Dukes of Chablais
- Dukes of Champagne
- Dukes of Chandos
- Dukes of Charost
- Dukes of Chartres
- Dukes of Châteauroux
- Dukes of Chateauvilain
- Dukes of Châtellerault
- Dukes of Châtillon
- Dukes of Chaulnes
- Dukes of Chevreuse
- Dukes of Chipre
- Dukes of Chiusa
- Dukes of Choiseul-Stainville
- Dukes of Ciudad Real
- Dukes of Ciudad Rodrigo
- Dukes of Civitanova
- Dukes of Civitella
- Dukes of Civrac
- Dukes of Clarence
- Dukes of Clarence and Avondale
- Dukes of Clarence and St Andrews
- Dukes of Clermont-Tonnerre
- Dukes of Cleveland-I
- Dukes of Cleveland-II
- Dukes of Clèves