Following the loss of the Levant and later Africa, the Mediterranean Sea was transformed from a "Roman lake" into a battleground between Byzantines and Arabs. This process would be furthered with the onset of the Muslim conquests in the 7th century. The re-establishment of a permanently maintained fleet and the introduction of the dromon galley in the same period also marks the point when the Byzantine navy began departing from its late Roman roots and developing its own characteristic identity. The first threat to Roman hegemony in the Mediterranean was posed by the Vandals in the 5th century, but their threat was ended by the wars of Justinian I in the 6th century. While the fleets of the unified Roman Empire faced few great naval threats, operating as a policing force vastly inferior in power and prestige to the legions, the sea became vital to the very existence of the Byzantine state, which several historians have called a "maritime empire". Like the empire it served, it was a direct continuation from its Imperial Roman predecessor, but played a far greater role in the defence and survival of the state than its earlier iteration. The Byzantine navy was the naval force of the Eastern Roman Empire (a.k.a. The Justinianic Wars, the Arab–Byzantine wars, the Byzantine–Bulgarian wars, the Rus'–Byzantine wars, the Byzantine–Norman wars, the Crusades and the Byzantine–Ottoman wars
Vandals, Ostrogoths, Umayyad and Abbasid Caliphates, Emirate of Crete, Fatimids, Slavs, Bulgarians, Rus', Normans, Genoa, Venice, Pisa, Crusader states, Seljuks, Anatolian beyliks, Ottomans Venice, Genoa, Pisa, Crusader states, Aydinids
1350) ĭroungarios tou ploïmou and thematic strategoi (8th–11th centuries),Ĭ. The imperial ensign ( basilikon phlamoulon) with the tetragrammic cross, carried by Byzantine warships in the 14th century, as described by Pseudo-Kodinos and illustrated in the Castilian atlas Conosçimiento de todos los reynos ( c.