EXARCHATE OF ITALY (OF RAVENNA). - Once Italy had been restored to the Empire after the fall of the Kingdom of the Ostrogoths, its government was held by the Byzantine commander who had achieved the final victory, Narses, with practically unlimited powers, including in the sphere of civil administration. When Narses was removed, around 568, by the emperor Justin II, he was not given a successor with the same attributions, and the Italian peninsula had only a civil governor, the praefectus praetorio Italiae, with his seat at Ravenna, and a supreme military command for the troops in Italy ceased to exist. But the need to reconstitute it, with powers pre-eminent over those of the civil officials, did not take long to become evident, when the rapid spread of the Lombard invasion as far as southern Italy showed how necessary a single military direction of the war operations was, capable of concentrating all the administrative resources of the peninsula on the needs connected with the renewed state of war. Therefore in 584 the emperor Maurice invested with the supreme military command in Italy a high dignitary of his court, whom he sent to Ravenna with the title of exarch.
The exarch (exarchus, Latin transliteration of the Greek term ἐξάρχος, "he who is first") also had his fixed seat at Ravenna, in the palatium that had been the residence successively of Honorius and of the last emperors in the West, of Odoacer and of Theodoric and his successors. Appointed by the sovereign, he was normally invested with the eminent dignity of patrician; he had military jurisdiction over the Italian peninsula, and effective control over the civil administration. The exact designation of this dignitary is therefore "exarch of Italy" ("exarchate of Italy"), not "exarch of Ravenna" ("exarchate of Ravenna"), as is commonly said. The generally accepted opinion that the first exarch was called Decius is also unfounded, because in reality the series of exarchs of Italy opens with Smaragdus, while only by error was this office also attributed to a Decius. In the course of the 7th century, with the praefectus praetoria having disappeared, the exarch definitively united the civil powers as well in his hands, and assumed the figure of a true and proper lieutenant of the emperor in the peninsula, and in certain periods he even had the authority to confirm papal elections. In the first half of the 8th century the resumption of the Lombard conquests through the work of Liutprand reduced the exarch to making his authority felt in a continuous and concrete way only over those of the territories of the peninsula that remained to the Empire which were in immediate contact with his residence. Only then did the designation "exarchatus Ravennae, Ravennantium" appear, which is found for the first time in the biography of Stephen II (752-57) of the Liber Pontificalis. It derived not from an innovation introduced into official Byzantine terminology but from the usage that had become established in the circles of the Church of Rome of thus designating precisely those territories over which in the last decades the exarch had had true direct jurisdiction, that is eastern Emilia, between the right bank of the Panaro and the Adriatic, between the Po di Volano-Comacchio lagoons area and the Pentapolis area on the left bank of the Musone. These were the territories that, having already largely fallen into the power of Liutprand, were completely conquered in 750-51 by Aistulf, who on 4 July 751 dated one of his privileges from the palatium of Ravenna, after the exarch Eutychius, the last of the series, had been taken prisoner. The majority of these territories was transferred to the temporal government of the Church of Rome as a result of the Carolingian donations beginning with Pepin. The history of the exarchate, no longer of Italy but of Ravenna, from 750-51 no longer Byzantine, from 756-57 onward is a chapter in the history of the temporal domains of the Church of Rome.