 From the 10th to the 13th centuries these cities built fleets of ships both for their own protection and to support extensive trade networks across the Mediterranean, leading to an essential role in the Crusades.The maritime republics, especially Venice and Genoa, soon became Europe's main gateways to trade with the East, establishing colonies as far as the Black Sea and often controlling most of the trade with the Byzantine Empire and the Islamic Mediterranean world.The county of Savoy expanded its territory into the peninsula in the late Middle Ages, while Florence developed into a highly organized commercial and financial city-state, becoming for many centuries the European capital of silk, wool, banking and jewelry.