In vain Venice attempted to defend her possessions in the Black Sea and in the Ægean; by the year 1500 most of her empire in the Levant was lost. The Turks, now in complete control of the northern route, proceeded to impose crushing burdens on the trade of the defeated Venetians. Florentines and other Italians who fared less hardly continued to frequent the Black Sea, but the entire trade suffered from Turkish exactions and from disturbing wars between the Turks and another Asiatic people--the Mongols. [Sidenote: Loss to the Italians] For some time the central and southern routes, terminating respectively in Syria and Egypt, exhibited increased activity, and by rich profits in Alexandria the Venetians were able to retrieve their losses in the Black Sea. But it was only a matter of time before the Turks, conquering Damascus in 1516 and Cairo in 1517, extended their burdensome restrictions and taxes over those regions likewise. Eastern luxuries, transported by caravan and caravel over thousands of miles, had been expensive and rare enough before; now the added peril of travel and the exactions of the Turks bade fair to deprive the Italians of the greater part of their Oriental trade. It was at this very moment that the Portuguese opened up independent routes to the East, lowered the prices of Asiatic commodities, and grasped the scepter of maritime and commercial power which was gradually slipping from the hands of the Venetians. The misfortune of Venice was the real opportunity of Portugal. [Sidenote: Columbus]