The prussian nobilty who aided their rulers wher known by what name no

Junkers

Explanation:

Junkers was the name for the nobility elite class in Prussia. These people usually would own large estates and pieces of land.

They were conservatives supporting the monarchy and had certain political power as they aided the rulers, military and were part of the diplomacy sector. They also had their part in the industry and business sector.

One of the prime examples of Junker is Otto von Bismarck who became chancellor.