It lay along the Adriatic coast between the rivers Marecchia and Misco immediately south of the core territory of the exarchate ruled directly by the exarch (the Ravennate), east of the Duchy of Perugia, another Byzantine territory, and north of the Duchy of Spoleto, which was part of the Lombard Kingdom of Italy (founded in 568).

The duchy probably extended inland as far as the Apennine Mountains, perhaps beyond, and its southernmost town was Humana (Numera) on the northern bank of the Misco.

[3] In 725, when the Exarch Paul wanted to lead a punitive expedition against the Duchy of Rome, where Pope Gregory II and the citizens had usurped imperial prerogatives and deposed and replaced the reigning duke, he raised troops in the Ravennate and the Pentapolis.

The inability of the exarch to impose his authority in Rome and his weakness in the Pentapolis was transformed into impotence when the "armies", that is, the Roman military aristocracies, of the duchies of the Ravennate, the Pentapolis, and Venetia rose in revolt declaring that they would protect the pope from the imperial decree, which Paul had been ordered to enforce throughout Italy (727).

[6] Liutprand attacked Ravenna and Cesena on the via Aemilia in 743, probably with the goal of controlling a passage through Byzantine territory to Spoleto.