Marcus Aurelius (121–180 AD) was a Roman emperor and one of the most renowned Stoic philosophers. He ruled from 161 to 180 AD during a challenging period of wars and crises, remaining a symbol of the philosopher-king. His work Meditations, written as personal reflections, is still regarded today as one of the most important texts of Stoic philosophy, full of insights on virtue, duty, and the transience of life. Marcus Aurelius was a man deeply committed to moral principles, placing the welfare of the empire above his ambitions. His reign was marked by efforts to preserve the unity of the state and a prudent approach to governance, despite the difficult struggles with barbarian invasions and internal crises.