Full Idea
A monarch has the highest power, while an autocrat or absolute ruler is one who has all the power.
Gist of Idea
Monarchs have the highest power; autocrats have complete power
Source
Immanuel Kant (Metaphysics of Morals I: Doctrine of Right [1797], §51)
Book Reference
Kant,Immanuel: 'Political Writings', ed/tr. Reiss,Hans [CUP 1996], p.161
A Reaction
If society is strictly hierarchical (like an army) then the monarch also has all the power. At the other extreme the one holding the highest power may have very little power, because so many others have their share of the power.