in antiquity, an officer sent by the emperors of the east into Italy, in quality of vicar, or rather prefect, to defend that part of Italy which was yet under their obedience, and particularly the city of Ravenna, against the Lombards. The exarch resided at Ravenna, which place, with Rome, was all that was left to the emperors of their Italian dominions. The first exarch was under Justinian the younger, in the year 567, after Belisarius and Narses had driven the barbarians out of Italy. The last was Eutychius, defeated by Adolphus king of the Lombards in 752.