Megasthenes was an eyewitness to the reign of Chandragupta Maurya, maker of the first India-wide empire (from ca. 321 BCE). The army with which he made that empire depended largely upon the supply of men, horses, elephants, and oxen, a sector which may be called military livestock. Megasthenes’ account of this large sector of government expense and the policies under which it operated gives important testimony about the causes of Chandragupta's success, namely the maintenance of a royal monopoly of horses, elephants, and arms, payment of the soldiers in peacetime and war, the demilitarization of the farmers, and the separation of the soldiers from the land. Over the long run of Indian history, from the Mauryan Empire to the present, the environmental roots of the political order lay in the complementary distribution of horse and elephant country, to the dry west and humid east of a line running down the middle of the Subcontinent; that is, respectively, the valleys of the Indus and the Ganga. The dominating power of India has always had its capital in elephant country, the valley of the Ganga, in cities from Pataliputra (Patna) to Kanauj to Delhi, in a position from which to control the eastward flow of horses and the westward flow of elephants to other states.