What are the landowners who give land to slaves called?

The slaves never received land, but the peasants could. During the Middle Ages, feudal lords gave land to peasants for use, for which they were forced to work for them and pay taxes in kind or in cash. This system was called the feudal system. In essence, such a system meant the obedience of one class of the population to another. Also in the Middle Ages there was a system of vassalage, where one feudal lord obeyed a more influential one.