In the feudal system in both Europe and japan, What did lesser nobles give to lords in exchange for grants of land?

Feudalism was a system where the king owned all the land, but exchanged the utilization  of it to members of the nobility in exchange for (usually) military services. It can be seen from  the description of feudal system that at heart of it was a system of relationships between  lords and their vassals, with rights and duties on both sides. It followed from this that medieval  lords did not have dictatorial powers over their vassal. For example, a lord don't have any rights to help  himself to his vassal’s property. Indeed, embedded within the system of western European feudalism  was the principle that a lord could not tax his subjects without their consent. Nobles gave loyalty and  military service.

The answer is athens and sparta.