What prevented the development of medieval cities?

1. The king could sharply raise taxes, thereby undermining the economic well-being of city dwellers. The same could be done by a feudal lord if the city was on his land;

2. Frequent wars, which brought the destruction of both economic and economic life, and the cities themselves;

3. Often robbers or pirates hunted trade on trade routes;

4. Lack of urban infrastructure, like the Roman, since in the Middle Ages they used mainly what remained from the times of antiquity.