Three Roman fleet models

Republican Rome built large polyreme fleets for peer conflict with Carthage, the Hellenistic kingdoms, and rival Roman factions. Repeated wars drove an arms race from triremes and quinqueremes to still larger ratings. Augustus inherited roughly sixty legions and several major fleets but cut the force after eliminating every symmetrical Mediterranean opponent. The Pax Romana made those capital-heavy formations neither affordable nor necessary. The later Dominate faced another transformation as fiscal weakness encouraged fleets to be raised only when crises demanded them.