How did Rome go from monarchy, to republic, to empire and then fall?

The transition from the Roman Republic to the Roman Empire began with the rise of Julsuis Ceaser and the subsequent civil wars. Caesar's assassination led to a power struggle, and eventually, his adopted son Octavian, later known as Augustus emerged as the sole ruler. Augustus established the Roman Empire which marked a shift from the Republican system of government to a monarchy. The empire thrived for several centuries but eventually faced numerous challenges. These factors combined led to the fall of the Western Roman Empire.