Final answer:
The Roman Republic was the form of government established in Rome around 500 BC following the removal of the last Roman king, characterized by elected consuls, a governing Senate, and checks on power to prevent tyranny.
Step-by-step explanation:
The form of government established in Rome around 500 BC was the Roman Republic. Following the overthrow of the last Roman king, Lucius Tarquinius Superbus, the Romans instituted a more democratic system where power was not held by a monarch, but instead by elected officials. This change was largely driven by a desire to prevent the rise of another tyrannical ruler. In the Roman Republic, the principal offices were held by two consuls, who were elected annually by the Centuriate Assembly and wielded significant executive power, including imperium. Oversight was ensured by limiting their term to one year and the responsibility of each consul to check the power of the other.
The Senate, made up of aristocratic administrators, controlled state finances and provided governance on a range of issues. Despite a professed distrust of centralized power, certain influential families often controlled voting blocks in both the Centuriate Assembly and the Senate, effectively guiding the direction of the Republic. The government structure included elements of democracy, aristocracy, and monarchy meticulously mixed to balance power within the state. This complex system lasted nearly 500 years and oversaw an extensive expansion of Roman power.