1. Islamic State: An Islamic state is a form of government which is ruled and governed on the basis of Islamic law.
2. Mongol Khanate: A Mongol Khanate was a medieval form of government ruled by Mongol kings.
3. City-State: These are sovereign states, sometimes described as very small countries which cover only one city and its surrounding areas.
4. Decentralized Feudalism: This form of government took hold in Europe and much of the world during the dark ages. This form of government usually meant very weak central power in the hands of a king or a single entity.