Arab–Byzantine wars: The Byzantine navy began a raid on the Nile Delta port city of Damietta, whose garrison was absent at the time. Byzantine navy: The Byzantine navy was the naval force of the Byzantine Empire. Like the state it served, it was a direct continuation from its Roman predecessor, but played a far greater role in the defence and survival of the state than its earlier iteration. While the fleets of the Roman Empire faced few great naval threats, operating as a policing force vastly inferior in power and prestige to the army, command of the sea became vital to the very existence of the Byzantine state, which several historians have called a "maritime empire". May 22, 853. Wiki link