Marcus Aurelius (121-180 CE) was Roman emperor from 161 to 180 and one of history's most revered Stoic philosophers. Born into a prominent Roman family, he was adopted by Emperor Antoninus Pius and carefully trained in governance and philosophy. His reign was marked by military conflict, including wars against Parthia and Germanic tribes, as well as the devastating Antonine Plague. Amid these pressures, he wrote Meditations, a series of personal reflections on duty, virtue, and self-discipline that later became a cornerstone of Stoic thought. Marcus Aurelius is remembered as the archetype of the "philosopher-king.".