ABSTRACT
Ports existed because of trade. As often as possible ships carried the goods exchanged. Transport over water was superior because of the simple physical relation between the lower levels of friction between a solid and a liquid than between a solid and a solid. The dramatic improvements in the technology of maritime transportation from the High Middle Ages to the late Renaissance made possible more efficient shipment of goods, attracted investment in shipping and in the end opened the door to greater trade. In the southern part of Europe mountains and the often hilly country meant that, with rare exceptions, rivers were short and difficult to use for transporting goods. In 1300 European ship design was still, for the most part, divided into two traditions, each dominant in a large region of the continent. Mediterranean vessels were different from those sailing the northern seas. In the south shipyards continued to produce galleys, propelled by oars as well as sails.
