The civilization(文化) of the Renaissance was the creation of prosperous cities and of rulers who drew substantial income from their urban subjects in the Italian city states and the countries of England and France. The commerce that kept cities alive also provided the capital and the flow of ideas that helped build Renaissance culture. During the early Middle Ages foreign trade had virtually come to a halt. By the 11th century, however, population growth and contact with other cultures through military efforts such as the Crusades(十字军东征) helped revive commercial activity. Trade slowly increased with the exchange of luxury goods in the Mediterranean region and various commodities such as fish, furs, and metals across the North and Baltic seas. Commerce soon moved inland, bringing new opulence to the citizens of towns along major trade routes. As traffic along these routes increased, existing settlements grew and new ones were established. The cities of Italy were located between western Europe and the area along the eastern shore of the Mediterranean Sea known as the Levant. Italy's leadership in the Renaissance was due in part to its central location for trade. The cities became important and wealthy commercial centers, and the riches collected by the merchants of Venice, Genoa, Milan, and a host of smaller cities supported Italy's political and cultural achievements. Important towns developed beyond Italy as well. Especially with the expansion of trade, towns grew along the Danube and Rhine rivers of Europe around the North Sea and the Baltic Sea and in the Low Countries of Belgium, Luxembourg and the Netherlands where northern and southern trade routes met. Wherever these towns were located, they became a unique element in a medieval world that up to this time was dominated by seignorialism(领主制), an agricultural system in which the primary economic and political relationship was between landowners and their tenants. The Renaissance ______.