When Cyrus entered Babylon in 539 B.C., the world was old. More significant, the world knew its antiquity. Its scholars had compiled long dynastic lists, and simple addition appeared to prove that kings whose monuments were still visible had ruled more than four millenniums before. Yet earlier were other monarchs, sons of gods and so themselves demigods, whose reigns covered several generations f present-day short-lived men. Even these were preceded, the Egyptians believed, b