 After the Battle of Actium, the period of major naval battles was over and the Romans possessed unchallenged naval supremacy in the North Sea, Atlantic coasts, Mediterranean, Red Sea, and the Black Sea until the emergence of new naval threats in the form of the Franks and the Saxons in the North Sea, and in the form of Borani, Herules and Goths in the Black Sea.In 27 BCE, Octavian was the sole Roman leader.His leadership brought the zenith of the Roman civilization, that lasted for four decades.