There are five main types of governments according to anthropologists: big man government, chiefdoms, complex chiefdoms, states, and empires. Big man governments were led by the strongest or most intelligent person in small tribes. Chiefdoms emerged around 5000 BC in villages led by hereditary chiefs. Complex chiefdoms had towns and cities led by a super-chief ruling over other chiefs. The first state was Sumer in 3500 BC with multiple levels of government. Empires had several levels of government and controlled multiple states, like the Akkadian Empire.