What is the difference between ancient Egypt and ancient Rome?
Rome began as a city-state and expanded its territory to
accommodate a growing population. As it expanded, it gained allies
tributary to it, and as its power grew it was invited to intervene
in external problems, which embroiled it in wars which expanded its
territories outside Italy. Politically it was controlled by the
oligarchic Senate with the checks and balances of popular
assemblies. However this system broke down resulting civil wars,
which was resolved by Augustus keeping up the facade of the
Republic and having reserve powers which enabled him to rule
autocratically without calling himself that.
Rome ended up, through good governance, providing stability in Europe and the Middle East for hundreds of years.
Egypt was a Monarchy with strong Theocratic support. While it from time to time expanded in the eastern Mediterranean, it was essentially the territory of the Nile River, where the Pharoah ruled and organised administrative support and services for the benefit of the people. Even the pyramid workers were free men, earning a living while the flood waters prevented them from working their plots.
With the successive conquest of Egypt by the Assyrians, Persians then Macedonians, a system of exploitation was built up, which reduced the small-farmers to serfs providing tax revenues for their foreign overlords. As Egypt became critical for the grain supply of the city of Rome, after he had defeated Antony and Cleopatra, Augustus reduced it to a province with a Roman governor.