f a young child is crowned the monarch, a Regent is often appointed to govern until the monarch reaches the requisite adult age to rule. Monarchs' actual powers vary from one monarchy to another and in different eras; on one extreme, they may be autocrats (absolute monarchy) wielding genuine sovereignty; on the other they may be ceremonial heads of state who exercise little or no power or only reserve powers, with actual authority vested in a parliament or other body (constitutional monarchy).