Although the eleventh century was in many ways Western Europe’s lowest point, it would also see the beginnings of Western Europe’s re-urbanization. One reason for these beginnings was that in those lands that had been part of the Western Roman Empire, city walls often remained, even if these cities had largely emptied of people. During the chaos and mayhem of the tenth and eleventh centuries, people often gathered in walled settlements for protection. Many of these old walled cities thus came to be re-occupied.

Another reason for the growth of towns came with a revival of trade in the eleventh century. This revival of trade can be traced to several causes. In the first place, Europe’s knights, as a warrior aristocracy, had a strong demand for luxury goods, both locally manufactured products and imported goods such as silks and spices from Asia. Bishops, the great lords of the Church, had a similar demand. As such, markets grew up in the areas around castles and churches, and, thus caused the formation of towns that served as market centers. Moreover, Viking raids had also led to a greater sea-borne trade in the North Sea and Atlantic. Often, Viking-founded markets served as the center of new towns, especially in those lands where the Romans had never established a state and which were not urbanized at all. The Irish city of Dublin, for example, had begun as a Viking trading post.