Final answer:
The English Channel was a key geographic feature in medieval England, acting as a defensive barrier and influencing military and political strategies along with the feudal and manorial systems that structured society and the landscape.
Step-by-step explanation:
A key geographic feature to medieval England was its natural protective boundary formed by the English Channel. This body of water served as a significant defensive barrier against invasions, particularly from continental Europe. The English Channel influenced medieval England’s military strategies and political relationships, especially during conflicts such as the Anglo-Saxon wars and the later Hundred Years' War. The feudal system, characterized by the distribution of land in exchange for military service, was another defining aspect of medieval England’s geography and society. The manorial system, with lands controlled by lords and worked by peasants, was also geographically significant as it shaped the rural landscape and economic productivity of the period.