The Arabs, although in the Middle Ages they had the monopoly of the trade, were not its originators, but merely continued an intercourse that had existed from remote antiquity. The mediæval geographers had very little precise knowledge; but in the Mappa Mundi of the tenth century, in the British Museum, the parts of northern Europe indicated with the fewest misconceptions are the countries of the amber trade. The rapid conquest of western Asia by the Arabs was followed by those internal dissensions which led to the formation of independent kingdoms. The Samanides, who reigned in Persia and dominated the shores of the Caspian Sea, were the principal cultivators of the North trade. The Arabs, if they had little taste for maritime commerce, were admirably adapted to be the leaders of great caravans, by which the riches of the East were spread into far lands. From Egypt they went across the Sahara to Nigritia, from whence they brought gold, ivory, and slaves. Passing through Persia and Cashmere they worked in the direction of India. Crossing the immense steppes of Tartary, they entered China by the province of Shen-si. Their caravans to Europe passed by Armenia on the south, and by Bokhara and Khorassan on the east. There were great fairs at Samarcand, Teheran, Bagdad, and other places. The merchants directed their course to the Caspian, and halted at Derbend before ascending the Volga. The itinerary of these pilgrims of commerce can be reconstructed from the Kufic coins and accompanying ornaments that have been found at Kazan, Perm, Tula, Moscow, Smolensk, Novgorod, St. Petersburg, and other localities. The finds of Arabic moneys in the Russian Empire have occurred almost exclusively in the country watered by the Volga, which was the line of communication for the Arabs with the Slavs and Scandinavians of the Middle Ages. The shores of Germany, Lithuania, and Sweden were visited. The most northerly discoveries of Kufic coins have been by the river Angermann, which empties itself in the Gulf of Bothnia. The islands of Gothland, Oland, and Bornholm appear to have been the centre of this commercial activity. Lithuania, Denmark, and Poland, especially the latter, have also yielded to the antiquarian investigator many evidences of intercourse with the Arabs. On the coasts of Pomerania and along the course of the Oder Kufic coins have been found, the southern limit being apparently in Silesia.