It's worth noting, it's big by any stretch of the imagination. But it's, at this time, the population is on the order of 50 million people. And based on the accounts that I've seen, that's almost half of the world population at that time. No empire in history, as far as we can tell, has ever had such a large fraction of the world's population under its control. And so that gives you a sense of, I guess you could say, how great or how large an empire this was. Now Darius the Great, he is also famous, especially from a Greek perspective, for going after the Greeks. You had these Greek revolts in these towns on the west coast of the Anatolian Peninsula.