What was the main function of the central government in early civilizations?

In early civilizations, the main function of the central government was to maintain order and stability through the establishment of laws and enforcement mechanisms. It coordinated large-scale projects such as irrigation and infrastructure, which were essential for agriculture and trade. Additionally, the government often managed resources, collected taxes, and organized defense against external threats, thereby ensuring the survival and prosperity of the society. Overall, it played a crucial role in unifying diverse communities under a common authority.