Feudal system

The feudal system was a European hierarchical social system based on service to a social superior. For the lower classes, the service was usually manual labour. Those above them in the system usually owed military service. Position within the hierarchy was normally determined by birth. Although the system had some flexibilities, notably through the institutions of the Church and the free towns (boroughs, burghs), its rigidity brought inefficiencies. The Black Death is often credited with hastening its end.