The Roman Republic was incredibly decentralized with more people working for the administration of the city of Rome than for the Roman state itself at the time of Caesar's conquest of Gaul. Extreme executive power existed, but not at the level of the imperial administration. Provincial governors had near absolute power and generals had control over their armies to a degree well beyond what any general today has. They were basically private mercenaries with the generals, not the state, being in charge of payroll for the soldiers. Local territories had near 100% control of their own affairs so long as they did not do anything to interfere with the tribute flowing to Rome.
This became more centralized over time and as it did more executive power was needed at the top level. Augustus centralized the army under state control. Emperors in the late empire had nearly dictatorial authority and a massive state bureaucracy under their control.
This became more centralized over time and as it did more executive power was needed at the top level. Augustus centralized the army under state control. Emperors in the late empire had nearly dictatorial authority and a massive state bureaucracy under their control.