What makes Marcus aurelius a hero?

Answer 1

Marcus Aurelius spent most of his reign at war. He fought wars against the Persians who had invaded Armenia, which was an ally of Rome and installed their own puppet king. They were defeated and then occupied Osroene (in northern Iraq) another client state of Rome and again installed their own puppet king. They were defeated again and this was the end of the war. He also fought war against the Marcomanni who together with the Iazyges the Lombards and other peoples were carrying out attacks deep into the empire. They were defeated, too.

Besides successfully in defending the empire from very serious threats, Marcus Aurelius was also a wise and fair ruler. He was one of the five good emperors. He had a keen interest and great expertise in the law and legal matters and was very active on legislation about the emancipation of slaves and the guardianship of orphans. He was also a stoic philosopher.