Venetian rule in the Ionian Islands to south, including their Greek and Italian names in parentheses: Cythera and Lefkada were additionally called ' or ' and " respectively by the Ottomans. During the Roman Empire, the Ionian Islands were variously part of the provinces of Achaea and Epirus vetus. These would form, with the exception of Cythera, the Byzantine theme of Cephallenia in the late 8th century. From the late 11th century, the Ionian Islands became a battleground in the Byzantine–Norman Wars. The island of Corfu was held by the Normans in 1081–1085 and 1147–1149, while the Venetians unsuccessfully besieged it in 1122–1123. The island of
Ionian Sea Sea, and from Piraeus westward. Calypso Deep, the deepest point in the Mediterranean at , is located in the Ionian Sea, at . The sea is one of the most seismically active areas in the world. The name "Ionian" comes from the Greek language . Its etymology is unknown. Ancient Greek writers, especially Aeschylus, linked it to the myth of Io. In Ancient Greek the adjective "Ionios" () was used as an epithet for the sea because Io swam across it. According to the "Oxford Classical Dictionary", the name may derive from Ionians who sailed to the West. There were