Explain why land was the main wealth in the Middle Ages?

This is due to the fact that at that time the land was the basis of agriculture. Also, the land was the object of the military. In addition, the land was handed out into the ownership of the feudal lords, who at the same time received the subordination of the population that lived on these lands. The very same era of the Middle Ages was full of feudal wars, where feudal lords fought for pieces of land in order to expand their power and influence.