An important inscription, found in the Roman market place in Athens, is here published for the first time. Although fragmentary, it preserves the text of a formal letter from Marcus Aurelius directed to the Athenians in the year A.D. 174/5. The Roman emperor's decisions in cases concerning office holding, membership of the council, and the appointment of the Athenian members of the Panhellenion (the council of cities established by Hadrian) are recorded. Elicited by a complaint to the emperor from prominent citizens, the letter also sheds light on the brutal political quarrels that swirled around the Athenian administrator, Herodes Atticus, builder of some of Athens's best-known monuments.