Battle of Sena Gallica
551 CE.
Shown on the map at 43.713°, 13.253°.
The Battle of Sena Gallica was a naval engagement fought in the autumn of 551 off the Italian Adriatic coast near Sena Gallica, (modern Senigallia). It marked a turning point in the Gothic War (535–554) between the Byzantines and the Ostrogoths (Goths). In 550, the Byzantine Empire was struggling to maintain control of Italy after earlier victories under Belisarius. Following his recall by Emperor Justinian I, disagreements among the remaining Byzantine commanders allowed the Goths to recover under their charismatic king, Totila. By 550, Totila had regained much of Italy, invaded Sicily, and built a fleet capable of challenging Byzantine control of the seas. He also sought to capture the remaining Byzantine strongholds on the Italian Peninsula and in particular the coastal city of Ancon. In autumn 551, the Goths besieged Ancon by land and sea while at the same time Totila sent part of his navy to raid nearby regions on the west side of the Balkan Peninsula. In response, the Byzantine generals Valerian and John the Sanguinary assembled a fleet and sailed toward Sena Gallica to provide relief to Ancon.
Text from the Wikipedia article Battle of Sena Gallica (551), licensed CC BY-SA 4.0.