Violent uprisings are historically common, including in the Roman Republic and later Roman Empire. They were crushed judiciously early by Rome's farmer-warriors (who had a very martial culture) and hundreds of years later by Rome's professional army. This is the primary way that states de facto have power.
You're right that you can't have a Pharaoh without a huge society built around one, but you don't get that society without a professional force policing the farming of the Nile, and you don't get successful farming of the Nile without a police force strong enough to oppose resistance / enforce retribution on "cheaters" with regard to water redistribution.
Regarding revolutions: sometimes the govt realizes it has a cancer and takes steps to cut it out or irradiate it. Sometimes the cancer wins and the entire body dies. Out of the ashes typically rises...autocracy. You only get something else when the power brokers actively strive to make such a thing, and even then you still frequently end up with autocracy.
History. Go read it.