The correct answer to this open question is the following.
The characteristics of an ideal Renaissance noble helped to serve his prince in the following way.
During the Renaissance times, the Nobles possed a considerable portion of the land in a city-state. Nevertheless, they offered their respects to their prince serving as military officers, as politicians or even as a personal adviser to the prince. The nobles were trained warriors that protected the prince but also were well-educated people that had good manners, culture, had an interesting conversation, were polite, and gracious.