The greatest politician and tactitions of the Roman era, Julius Caesar engaged in a series of wars is Gaul, moder
day France occupied by a number of barbarian tribes. He added Gaul to the empire and
soon desired more power. He defeated the armies of Pompey, his greatest rival, and marched into the city of Rome. He became sole ruler of the
Roman Republic and was advised by the Senate of Rome. He was not, however, the first emperor. The
Roman Republic was replaced by the Roman Empire during the reign of Rome's first emperor Augustus Caesar.