As an advancing tide, engulfing in its progression the stretches of ooze-land which lie in its onward path, sends scurrying before it flights of waders and other shore-haunting birds, driven from their feeding grounds, so the great Mongol wave which was creeping upon Eastern Europe drove before it disordered troops of the Polovtzi nomads, seeking among their old enemies the safety which their desert fastnesses no longer afforded. Into the principality of Kiev poured the fugitives, bringing with them droves of horses, camels, cattle, and buffaloes--a wonderful and misgiving sight to the staring Russians, who saw their fierce, untamable foes, the incarnation to them of all that was barbarous, outlandish, and terrible, cowering and fleeing from some unseen horror behind. That the wolf of the steppes should come to lie down, panting and trembling, with the lamb, boded the advent of anything but a millennium. The accounts given by the Polovtzi khans of the Mongol hordes which had swept the tribes of Western Asia before their advancing host, roused the Russian princes to a sense of the danger they courted by their disunion, and gathered them together in the old capital to deliberate on a common action in opposition to the threatened invasion. Mstislav of Galitz, erstwhile of Toropetz, Mstislav Romanovitch (of the house of Smolensk), Prince of Kiev, Daniel of Volhynia, Mstislav of Tchernigov, and other princes of less importance, held high counsel between them, and debated the means of averting the Mongol advance; and as they paused in their deliberations to mark the unwonted caravans and uncouth brutes of the desert that thronged the streets and approaches of Kiev, it must have been borne in upon them that already Asia had overflowed her limits and swept the Russian lands into her embrace. And while, taking heart of grace from the assemblage of so many important princes and the leadership of the redoubtable Mstislav of Galitz, they consider how best to oppose these fearsome enemies, it will be of interest to learn something of the history of this Mongol horde, this mushroom growth that had over-spread the northern empire of China, made a desolate waste of Persia, carried its arms into Hindostan, and risen to be the greatest power in Asia, and which was now threatening to attack the outskirts of Christendom.