coast resisted until 1000, when doge Pietro II Orseolo conquered the northern and central part of the region. Privileges in the Holy Empire worked well together in combination with supremacy in the Adriatic Sea and a chart of the Byzantine Emperor of 992. In compensation for military aid against the Arabs of southern Italy, the Byzantine emperor Basil II had reduced the tax for the ships by half. In addition Venetians started trade with Tunisia and Alexandria in Egypt where they delivered wood, weapons, metal and slaves, even though the trade with Islam was sometimes banned. Emperor Leo V (813–820) had already forbidden this trade,. Venice played an important role in Byzantine trade, as a commercial outlet and a supply center to the empire. Byzantine exports, such as luxury silk cloth, spices, precious metals - went through Venice, and from Venice, slaves, salt, and wood were shipped towards Byzantium and the Muslim Levant. After the 9th century, however, Venice became increasingly independent from the Byzantine Empire. The Golden Bull of 1082, issued by Alexios I Komnenos in return for their defense of the Adriatic Sea against the Normans, granted Venetian merchants with duty-free trading rights, exempt from tax, throughout the Byzantine Empire in 23 of the most important Byzantine ports, guaranteed them property-right protections from Byzantine administrators, and given them buildings and wharfs within Constantinople. These concessions greatly expanded Venetian trading activity throughout the Eastern Mediterranean. In the Holy Land, which was conquered by the Crusaders at about 1098, Venice gained the right of free trade, because it had helped Gottfried von Bouillon in 1100 and he subsequently conquered Tyros, the trade central in Syria. The colonies enjoyed autarchy and autarky. From Syria to Little Armenia they conducted their trade deep into Asia, with future colonies being eyed in Alexandria and the Maghrib. The counterpart of the privilege of 1258 became the one of 1084 that emperor Henry IV ceded for his whole realm. Deeply mired in the Investiture Controversy he allowed Venetians to trade in his whole realm, but his subjects were not allowed to extend their trading activities over Venice. Together with the monopoly in the Adriatic Sea and the staple, and the fact that merchants could only trade in Venice with the intermediates that the city provided, Venice was on the way to monopolizing trade between West and East. The merchants of the 1082 Holy Empire had