Seneca (epist.

vii.) shows the feelings of a man.] The recent danger, to which the person of the emperor had been exposed in the defenceless palace of Milan, urged him to seek a retreat in some inaccessible fortress of Italy, where he might securely remain, while the open country was covered by a deluge of Barbarians.

On the coast of the Adriatic, about ten or twelve miles from the most southern of the seven mouths of the Po, the Thessalians had founded the ancient colony of Ravenna, [60] which they afterwards resigned to the natives of Umbria.

Augustus, who had observed the opportunity of the place, prepared, at the distance of three miles from the old town, a capacious harbor, for the reception of two hundred and fifty ships of war.

This naval establishment, which included the arsenals and magazines, the barracks of the troops, and the houses of the artificers, derived its origin and name from the permanent station of the Roman fleet; the intermediate space was soon filled with buildings and inhabitants, and the three extensive and populous quarters of Ravenna gradually contributed to form one of the most important cities of Italy.