What were the roles of nobles, and how did they train for these?

The expansion of centralized royal power and law involved limiting the power of the nobility, but rulers also worked through nobles, who retained their privileged status and cultural importance. In fact, despite political, scientific, and industrial revolutions, the nobility continued to hold real political and social power in Europe into the nineteenth century. In order to account for this continuing influence, it is important to understand the development of the nobility in the High Middle Ages.