Freeman, on account of the Romanesque character of the architecture, thought it probable that it really belongs to the time of the Lombard kings, and his opinion is shared by Ricci and Rivoira, who consider it to be a guardhouse erected by the exarchs, recent explorations having made it clear that it was an addition to the palace, while mosaic pavements and an atrium once surrounded by arcades really belonging to the latter were found in 1870 behind S.
Its connexion with that empire - or, in other words, its dependence upon Constantinople - lasted for more than 200 years, during which period, under the rule of Narses and his successors the exarchs, Ravenna was the seat of Byzantine dominion in Italy.
Among the former it appears to have become a sort of ex officio title of the Byzantine vicegerents of Italy, the exarchs of Ravenna; among the barbarian chiefs who were thus dignified were Odoacer, Theodoric, Sigismund of Burgundy, Clovis, and even in later days princes of Bulgaria, the Saracens, and the West Saxons.
Hence came the invasion of Alboin (568), which wrested the greater part of Italy from the empire, and changed the destinies of the peninsula.2 1 Gibbon's statement that Narses was "the first and most powerful of the exarchs" is more correct in substance than in form.
Of these, the most important were the exarchs of Ravenna.