What facts indicate the emergence of feudal relations?

From the beginning of the decentralization of power in the Middle Ages, feudal-serf relations began. After successful wars, European kings rewarded their soldiers with land plots if they continued to serve the monarch. So the soldier became a landowner, who also received serfs as a reward. Another fact of the emergence of feudal relations is serfdom. Unlike a slave, a serf had minimal rights and ran his own household with his lord. The vassals of their feudal lords also received land allotments for serving their service, dividing the society into a monarch, large and small landowners and peasants.