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
Sea of Marmara , with dimensions .Its greatest depth is . The sea takes its name from Marmara Island, which is rich in sources of marble, from the Greek "μάρμαρον" ("marmaron"), "marble". The sea's ancient Greek name "Propontis" derives from "pro-" (before) and "pontos" (sea), deriving from the fact that the Greeks sailed through it to reach the Black Sea, "Pontos". In Greek mythology, a storm on Propontis brought the Argonauts back to an island they had left, precipitating a battle where either Jason or Heracles killed King Cyzicus, who mistook them for his Pelasgian enemies. The surface salinity of the sea averages