ABSTRACT
THE development of navigation was proportionate to that of trade and to the security of the seas; it declined when commerce grew more restricted and the pirates, taking advantage of the division and weakening of the Empire, resumed their sway in certain regions. For the war and police fleets which were stationed at Misenum and at Ravenna and the squadrons whose stations were Aquileia and Fréjus did not survive—any more than did the old organization of the legions—the repeated blows of the third and fourth centuries.
