The Orthodox Church placed the diocese of Tenedos under the metropolitanate of Mytilini during the ninth century, and promoted it to its own metropolitanate in early fourteenth century. By this time Tenedos was part of the Byzantine Empire but its location made it a key target of the Venetians, the Genoese, and the Ottoman Empire. The weakened Byzantine Empire and wars between Genoa and Venice for trade routes made Tenedos a key strategic location. In 1304, Andrea Morisco, a Genoese adventurer, backed by a title from the Byzantine emperor Andronikos III, took over Tenedos. Later, sensing political tension in the Byzantine empire just before the Second Byzantine Civil War, the Venetians offered 20,000 ducats in 1350 to John V Palaiologos for control of Tenedos. When John V was captured in the Byzantine civil war, he was deported to Tenedos by John VI Kantakouzenos.