Marcus Aurelius Antoninus was a Roman emperor from 161 to 180 and a Stoic philosopher. Best known for his Meditations on Stoic philosophy. He was the last of the rulers known as the Five Good Emperors, and the last emperor of the Pax Romana (27 BC to 180 AD), an age of relative peace and stability for the Roman Empire.

“The happiness of your life depends upon the quality of your thoughts.” ― Marcus Aurelius, Meditations