Thus the Phoenicians linked in a vast commercial chain Britain, Iberia (Spain), and India; while the Guadalquiver, the Nile, the Euphrates, the Tigris and the Indus, served as highways for their trading enterprise. From Byblos, Tyre, Sidon and other emporiums, they sent out caravans far and wide into Arabia and Fore-Asia. The products of their art and industry were reputed most exquisite even as early as the epoch of the Iliad, and they were vain enough to look on themselves as the pivots of the world's prosperity, and the Scriptures repeatedly mention the pride and denounce the vices of the Phoenician cities. What their merchants bought or received in barter in Asia or in Egypt, they exchanged for the rough products of Greece, Spain, Albion, Libya, and the lands on the Euxine: these consisted principally of grains, hides, copper, tin, silver, gold, and indeed all kinds of marketable objects. Their central situation for the commerce of the known and almost of the unknown world, especially favored the slave-trade. Accordingly Phoenician slaves became more and more valuable, and a continually extending market produced a constantly increasing demand. In all probability the inland caravan excursions afforded the principal supplies for their immense slave traffic; but they also bought, stole, and kidnapped from every possible place and by every conceivable stratagem--just as modern American slave-traders do. In this horrid industry they visited every shore. They carried it on among the Greeks, among the Barbarians of the Hellespont and the Pontus, among the Iberians, Italians, Moors and other Africans. Natives of Asia were sold to Greece and other European countries, while Syria and Egypt were furnished with European slaves. The great majority of these slaves belonged to what is called the Caucasian race, and negroes constituted a comparatively insignificant part. In return for these white chattels the Phoenicians bartered the products of Egypt and of Fore-Asia. The Phoenicians, then, were the great, and, in all probability, the exclusive slave-traders of those times. The traffic had its chief centre in Byblos, Sidon and Tyre--the depots, bazaars, and storehouses of which were always glutted with human merchandise.