polygarchy
/pɒlɪˈɡɑːrki/ or /pɔːlɪˈɡɑːrki/Definitions
1. noun
A form of government in which a single person holds power, but there is no centralized authority other than the ruler, with local autonomy and often polygamy.
“The ancient Sumerian city-states formed a loose polygarchy, with each city ruled by a king but with a great deal of local autonomy.”