The Duchy of Rome (Latin: Ducatus Romanus; Greek: Δουκᾶτον Ῥώμης, romanized: Doukâton Rhṓmēs) was a state within the Byzantine Exarchate of Ravenna. Like other Byzantine states in Italy, it was ruled by an imperial functionary with the title of dux. The duchy often came into conflict with the Papacy over supremacy within Rome. After the founding of the Papal States in 756, the Duchy of Rome ceased to be an administrative unit and "dukes of Rome", appointed by the popes rather than emperors, are only rarely attested.
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