Rome faced numerous conflicts during the days of the Republic, including defending the Italian peninsula against the Gauls, and fighting three 'Punic Wars' against its rival neighbor, Carthage. Rome gained a significant amount of land and capital from its victories in the Punic Wars, but these victories would ultimately lead to the Republic's fall. Political instability and military reforms gave rise to dictatorships, such as those of Sulla and Julius Caesar. Caesar became the most powerful man in Rome, and after his assassination at the hands of Optimate senators, Rome suffered a series of civil wars. These civil wars resulted in the republic's transition to an empire, beginning with the reign of Augustus Caesar in 27 B.C.