Marcus Aurelius Antoninus was a Roman emperor from 161 to 180 CE and is best known today as a philosopher-king, whose writings on Stoic philosophy have earned him enduring respect. Born on April 26, 121 CE, in Rome, Marcus came from a prominent, wealthy family. He was adopted by Emperor Antoninus Pius, following Emperor Hadrian's plan for imperial succession, which eventually placed Marcus in line for the throne. Marcus ruled as emperor alongside Lucius Verus from 161 CE until Verus's death in 169 CE, after which he ruled alone, later sharing power with his son Commodus toward the end of his reign. Despite his philosophical nature, Marcus Aurelius spent much of his rule dealing with military conflicts, including wars against Germanic tribes and Parthians, as well as internal plagues and economic challenges. He is best remembered for his personal journal, Meditations, written in Greek during his military campaigns. Though intended for his own self-reflection, Meditations has become a cornerstone of Stoic philosophy, offering insights on duty, resilience, self-discipline, and the transient nature of life.