This sea called Caspian is hemmed in to the west by the Caucasus : towards the east and the sunrise there stretches from its shores a boundless plain as far as the eye can see. The greater part of this wide plain is the country of the Massagetae, against whom Cyrus was eager to lead his army. For there were many weighty reasons that impelled and encouraged him to do so: first, his birth, because of which he seemed to be something more than mortal; and next, his victories in his wars: for no nation that Cyrus undertook to attack could escape from him.