the Treaty of Nymphaeum (1261) with the Byzantine emperor Michael VIII Palaeologus, which, in exchange for the aid to the Byzantine reconquest of Constantinople, actually ousted the Venetians from the straits leading to the Black Sea. The main Genoese commercial bases were Chios and Mytilene in the Aegean Sea, and Caffa, the major trading center between Mongol-ruled Eastern Europe and Central Asia and Western Europe. Other colonies included Cembalo (modern Balaklava), Soldaio (Sudak), Vosporo (Kerch), while other were located on the Azov Sea, including Tana (Azov), Matrega (Taman), Mapa (Anapa), Bata (Novorossijsk) and others, on the Abkhazian coast, such as Savastopoli (Sukhumi), or on the Ukrainian coast, such as Salmastro or Moncastro (Bilhorod-Dnistrovskyi), Ginestra (now part of Odesa). During the greatest period of expansion, between the 13th and 15th century, the Republic of Genoa had many colonies and commercial/military ports in the region where is now present-day Romania. The largest Genoese colonies in the region were Calafat, Licostomo, Galați (Caladda), Constanța, Giurgiu (San Giorgio) and Vicina. These Genoese settlements served primarily to protect the maritime trade routes that made the Republic a power in this area. In 1155 Genoa was given a fondaco (store and market quarter) at Galata (Pera), facing Constantinople, by emperor Manuel Komnenos, although in the following century the relationship with the Byzantine Empire were often strained. In 1201 the city also obtained privileges and quarters from the Kingdom of Armenia. Pera fell to the Ottoman forces in 1453, when all of Constantinople was captured. Meanwhile, Chios remained a fief of the Giustiniani family until the Ottoman conquest in 1566. There were some 33,000 descendants of the Genoese colonists in Constantinople and Izmir in 1933. Genoa had also conquered the island of Tabarka off the Tunisian coast, which was held by the Lomellini family from 1540 to 1742. Part of the latter's citizens later moved to Carloforte in Sardinia. In addition to its possessions in Crimea, the most important Genoese colonies in the Black Sea area were Taman, Copa, Bata, Maurolaca and Mapa, most of them would survive under Genoese rule until the late 15th century. The decline of the Genoese colonies in Crimea coincided with the Ottoman expansion in the late 15th century. Aside from the Crimean cities, Genoa also lost its lands in the Taman Peninsula, which had belonged to the noble Ghisolfi family. Other losses included the commercial bases of Licostomo in Moldavia and