Righto. It appears all the early civilizations were theocratic in origin. When you’re a farming people weather becomes absolutely critical. The guy who is able to convince people he’s got connections Upstairs gathers more and more power.
Eventually becoming a God-King. This appears to be pretty much what happened in Egypt, the Indus, China, the Andes and Meso-America.
The main exception I’m aware of is Sumer. There, unlike Egypt, the country was split up into many city-states. These needed military leaders who gradually gained power relative to the priests and eventually became the first true secular rulers. Kings, IOW.