people who held a lot of power, but not as much as the monarch, during the Middle Ages were called...

The people who held a lot of power, but not as much as the monarch, during the Middle Ages were called nobles or aristocrats. They were usually landowners and controlled large estates, and held significant influence over local governance and served as advisors to the monarch. Nobles were often granted titles such as dukes, earls, barons, or knights, depending on their rank and territory.