Siberia is emphatically the "Land of the North." Its name has by some etymologists been identified with "Severia," a term formerly applied to various northern regions of European Russia. The city of Sibir, which has given its name to the whole of North Asia, was so called only by the Russians, its native name being Isker. The Cossacks, coming from the south and centre of Russia, may have naturally regarded as pre-eminently the "Northern Land" those cold regions of the Ob basin lying beyond the snowy mountains which form the "girdle of the world." Long before the conquest of Sibir by the Cossacks, this region was known to the Arab traders and missionaries. The Tatars of Sibir were Mahommedans and this town was the centre of the great fur trade. The Russians themselves had constant relations with the inhabitants of the Asiatic slopes of the Urals, and the Novgorodians were acquainted with the regions stretching "beyond the portages." Early in the Sixteenth Century the Moscow Tsars, heirs of the Novgorod power, called themselves lords of Obdoria and Kondina; that is of all the Lower Ob basin between the Konda and the Irtish confluence, and the station of Obdorsk, under the Arctic Circle. Their possessions--that is, the hunting grounds visited by the Russian agents of the Strogonov family--consequently skirted the great river for a distance of 600 miles. But the Slav power was destined soon to be consolidated by conquest, and such is the respect inspired by force that the successful expedition of a Cossack brigand, on whose head a price had been set, was supposed to have led to the discovery of Siberia, although really preceded by many visits of a peaceful character. Even still the conquering Yermak is often regarded as a sort of explorer of the lands beyond the Urals. But he merely establishes himself as a master where the Strogonov traders had been received as guests. Maps of the Ob and of the Ostiak country had already been published by Sebastian Munster and by Herberstein a generation before the Cossacks entered Sibir. The very name of this town is marked on Munster's map.