The Duchy of Rome was a duchy within the Byzantine Empire. Like other Byzantine states in Italy, it was ruled by an imperial functionary with the title dux. The duchy often came into conflict with the Papacy over supremacy within Rome. The duchy was founded by the conquest of Emperor Justinian I in 533 AD. After the founding of the Papal States in 751, the title of Duke of Rome fell into disuse.
Peter (? - 725)
Marinus (725 - ?)
Toto (767 - 768)
John (772– ?)
Theodore (772 - 795)
Leoninus (?) (Under the Papacy)
Sergius (815) (Under the Papacy)