Final answer:
Rome's government evolved from a kingdom with hereditary rulers to a republic with an elected assembly and consuls, and finally to an empire with centralized power and an expanded bureaucracy.
Step-by-step explanation:
The government of Rome notably changed from a kingdom to a republic and finally to an empire over the course of its extensive history. Initially, as a kingdom, Rome was governed by hereditary monarchs. During the period of the Roman Republic, beginning in 509 BCE, authority transitioned to elected leaders, with the Centuriate Assembly electing consuls and the Senate comprising aristocratic administrators.
This changed with Julius Caesar and Augustus Caesar, who shifted Rome towards an imperial government. The Empire saw increased centralization and bureaucratic expansion, which coincided with Christianity's growing influence. The Senate's role evolved from a powerful state body to a city council with limited influence over state affairs. As Rome grew, it established a government with colonial and municipal levels, all of which were an extension of Roman power and constitutional models.
The Senate's influence varied throughout these changes, diminishing during the imperial period. The growth of Rome required government on colonial and municipal levels, extending Roman constitutional principles.