An autocracy is a system of government in which supreme power is concentrated in the hands of one person, whose decisions are subject to neither external legal restraints nor regularized mechanisms of popular control (except perhaps for the implicit threat of a coup d'etat état or mass). insurrectionecause autocrats need a power structure to rule, it can be difficult to draw a clear line between historical autocracies and oligarchies. Most historical autocrats depended on their nobles, the military, the priesthood or other elite groups. Some autocracies are rationalized by assertion of divine right.