Well, this is only somewhat related, but contrary to public belief, Caesars last words were not, "Et tu, Brute," but instead in Greek, as, "Και εσείς, ο Βρούτος?" (Or its rough equivalent, I'm not a Greek speaker). Roman elites spoke Greek to show their level of status in society, much like Imperial British elites spoke French, and because many famous works by well respected philosophers and play-writes were in Greek, so any well-respected Roman could read and speak Greek in order to show how learned he was.