boundaries ever in advance, his people founded Nijni Novogorod at the confluence of the Oka and Volga, which soon eclipsed the glories of its namesake. Thus, at the beginning of the thirteenth century, Russia was studded with republics governed by oligarchies, and resembling in most essentials those which were in process of formation in Italy. The popular liberties were already undermined by the encroachments of prince and noble, fostered, for selfish ends, by the Church; but material civilisation was on the increase, and, had it been permitted to grow on Slavonic lines, the arts which adorn and sweeten life would have found a home in Russia. This nascent culture was destroyed by an eruption of foes more ruthless than those who had completed the ruin of imperial Rome, and the clock of moral and industrial advance was put back by several centuries. Human progress is stimulated by the tendency exhibited by population to outstrip the means of subsistence. No sooner has a community attained a certain degree of physical well-being than this great natural law comes into play. The numbers begin to press too heavily on the land, and the younger and more vigorous are driven to seek new spheres for their energies. They colonise distant lands, subdue their weaker neighbours, and the mother state becomes a centre of dominion, of luxury and its attendant arts. It is the process which gave the world the priceless boon of Greek civilisation, and made Rome a storehouse whence we moderns have drawn our principles of law and government. In the earlier centuries of our era the regions lying between the Gobi Desert and Lake Baikal were the habitat of a congeries of Mongolian tribes belonging to the Ural-Altaic family.[527] They were a pastoral race, living in tents of felt and skins which they moved when the surrounding pastures had been exhausted by their flocks and herds.