What was the unwritten policy between the Prussian monarchy and the Junkers?

It was part of the European tapestry that the Monarchs sought to repress the nobility who were for the most part the landed aristocracy. So to in Prussia. To keep good-willed control of this aristocracy, military commissions were awarded, and the nobility were allowed a free hand over the peasants. Thus we have the Prussian monarchy ruling the nobles and the nobles ruling the peasants. Everyone but the peasants were happy, but they had no power. Viewing this from another angle, the peasants could feel secure that their leaders would be there to defend them against other foreign powers.