owed the sultan "fidelity", "truthfulness", and "submission", and an annual tribute, which was in 1481 defined at 12,500 gold coins. The sultan guaranteed to protect Ragusa and granted them extensive trading privileges. Under the agreement, the republic retained its autonomous status and was virtually independent, and usually allied with the Maritime Republic of Ancona. It could enter into relations with foreign powers and make treaties with them (as long as not conflicting with Ottoman interests), and its ships sailed under its own flag. Ottoman vassalage also conferred special trade rights that extended within the Empire. Ragusa handled the Adriatic trade on behalf of the Ottomans, and its merchants received special tax exemptions and trading benefits from the Porte. It also operated colonies that enjoyed extraterritorial rights in major Ottoman cities. Merchants from Ragusa could enter the Black Sea, which was otherwise closed to non-Ottoman shipping. They paid less in customs duties than other foreign merchants, and the city-state enjoyed diplomatic support from the Ottoman administration in trade disputes with the Venetians. For their part, Ottomans regarded Ragusa as a port of major importance, since most of the traffic between Florence and Bursa (an Ottoman port in northwestern Anatolia) was carried out via Ragusa. Florentine cargoes would leave the Italian ports of Pesaro, Fano or Ancona to reach Ragusa. From that point on they would take the land route Bosnasaray (Sarajevo)–Novibazar–Skopje–Plovdiv–Edirne. When, in the late 16th century, Ragusa placed its merchant marine at the disposal of the Spanish Empire on condition that its participation in the Spanish military ventures would not affect the interest of the Ottoman Empire; the latter tolerated the situation as the trade of Ragusa permitted the importation of goods from states with which the Ottoman Empire was at war. Along with England, Spain and Genoa, Ragusa was one of Venice's most damaging competitors in the 15th century on all seas, even in the Adriatic. Thanks to its proximity to the plentiful oak forests of Gargano, it was able to bid cargoes away from the Venetians. Decline of the Republic With the Portuguese explorations which opened up new ocean routes, the spice trade no longer went through the Mediterranean. Moreover, the discovery of the Americas started a crisis of Mediterranean shipping. This was the beginning of the decline of both the Venetian and Ragusan republics. Charles VIII of France granted trading rights to the Ragusans in 1497, and