Two elected officials called consuls commanded the military: Roman Republic. During the Roman republic, each year two consuls were elected to serve a join one year term. Each month one of them ruled the empire and commanded the military.A single individual held most of the power in the government: Roman Empire.During the Roman Empire, Rome was ruled by an emperor. The emperor was the center of power in the Roman Empire, he was the political and religious authority. Which led to the period of Dominate, also called the late Roman Empire.A large professional army was created: The professional Roman Army was created during the Roman Kingdom, when Rome had a monarchy. The most powerful senators fought among themselves to control Rome: Roman Republic.During the Roman Republic Senate held most of Rome’s power. Because of that, senators fought amongst themselves for influence. It was during this moment that Julius Cesar became known.