Basically entire Europe was a warzone from the end of the Roman period to... oh, Ukraine.. well, Europe still
is a warzone but much less so now than in the past centuries.
The middle ages wars didn't really involve the population. They were more a matter of aristocracy. Cities were raized, since those where the way to control land, but you generally left the peasants and their lords alone.
Peasants really didn't care who was the king. Nationalism was not a concept yet! Somebody was your liege lord since feudal competition abhors vacuum, but you didn't have much say in it. He probably didn't even speak your language.
They way medieval states handled their state business was that more or less, you had the king, the king had a large box called the "treasury", and then the aristocrats who had bent the knee for the king brought taxes to that box.
These barons and whatnots then extracted some surplus from the land as taxes for themselves, and for the king.
But this was really inefficient in pre-bureaucratic times! The state could maybe utilize 1 percent of the output since nobody knew how much a person produced, so everything was very, very, approximate.
So basically the 'state' and the 'people' were quite disconnected, and wars mostly affected the 'state' and not the people that much.
Wars really were a way to extend policy - which meant basically kings competed from what area they could command the nobility to carry taxes for them.
There was none of this 'total war' business. There were no industries to destroy, no population whose morale to pummel - since the morale of the population did not matter!