The emperor was the head of state and held the following powers:
- Executive: As emperor, Marcus Aurelius had the authority to make and enforce laws, appoint and dismiss officials, and command the military. He was also the chief executive of the government and responsible for the day-to-day administration of the empire.
- Legislative: Marcus Aurelius shared legislative power with the Roman Senate. The Senate was a body composed of wealthy and influential citizens, and it had the power to pass laws and approve or reject imperial decisions.
- Judicial: Marcus Aurelius was the highest judicial authority in the empire. He could hear appeals from lower courts and issue pardons and commutations. He also had the power to appoint judges to the various courts throughout the empire.
- Military: As commander-in-chief of the Roman army, Marcus Aurelius led military campaigns against the Parthians, Germans, and other enemies of the empire. He was a skilled military leader and won several important victories.
- Religious: Marcus Aurelius was also the chief religious authority in the empire. He was responsible for overseeing the Roman state religion and promoting religious harmony. Although he was himself a Stoic philosopher, he tolerated other religious beliefs and protected religious minorities.