The fortunes of the town increased considerably when it joined the First Crusade: its participation brought great privileges for the Genoese colonists, which moved to many places in the Holy Land. The apex of Genoese fortune came in the 13th century with the conclusion of the Treaty of Nymphaeum (1261) with the Byzantine emperor Michael VIII Palaeologus. In exchange for aiding the Byzantine reconquest of Constantinople, this led to the ousting of the Venetians from the straits leading to the Black Sea, which quickly became a Genoese sea. Shortly afterwards, in 1284, Pisa was finally defeated in the Battle of Meloria by the Genoese Navy.