When Rome's Republic was formed, Rome was a mere small city-state, easily managed. However, as time went on, politicians found it harder to maintain the growing country. Extremely wealthy landowners, known as patricians, began to have more and more political power. After the second Punic War, marking the destruction of Rome's enemy Carthage, the Roman economy and trade grew at a fast pace. Rich landowners and merchants were able to buy up most of the country land. Under Roman law, only landowners could serve in the military, but with the rich owning the land, the number of available soldiers dwindled. This caused instability in the Roman military.
After 8 years Julius Caesar returned. The senate was afraid that he might march on Rome with his loyal army. The senate's fears proved correct. Pompey could not organize a counter offensive in time to save Rome, so he was forced to flee. Caesar marched into the city and appointed himself dictator. While the senate still existed, it was practically powerless against Caesar's commands.
Desperate politicians Brutus and Cassius plotted against Julius and eventually killed him, stabbing him in the back on March 15, 44 B.C. The conspirators believed that the senate would regain control of Rome. However, strong generals Mark Antony and Marcus Lepidus unofficially established their power by intimidation through their armies. In the ensuing years the Second Triumvirate was formed. This consisted of Mark Antony, Lepidus, and Julius Caesar's nephew Octavian, who had demanded a position in the senate after Julius' death. The three men swept the senate with terror, killing Cicero, who was the greatest supporter of the republic. Antony and Octavian received no more opposition from the senate and were supreme rulers. They were powerful enough that they didn't need Lepidus anymore, so they betrayed him by knocking him out of their alliance. Antony took control over Eastern Rome, while Octavian controlled Western Rome. After a few years, in 36 B.C. Octavian, needing an excuse to wage war on Antony, accused him of being disloyal to Rome by becoming involved with Cleopatra of Egypt. Octavian attacked Eastern Rome and defeated Antony. Octavian, who had changed his name to Augustus, was finally supreme ruler over Rome.
The republic had died. While the senate still existed, it had little say in government matters and could certainly not challenge the word of the emperor. Ten Caesars came after Augustus to rule over Rome. Despite the crippling of the Republic, Rome continued to prosper and expand for several centuries until its eventual decline.