If we look for the causes which rendered the defeat of the brave Russian nation so complete, we may, with Karamsin, indicate the following: 1. Though the Tartars were not more advanced, from a military point of view, than the Russians, who had made war in Greece and in the West against the most warlike and civilized people of Europe, yet they had an enormous superiority of numbers. Batu probably had with him five hundred thousand warriors. 2. This immense army moved like one man; it could successively annihilate the droujinas of the princes, or the militia of the towns, which only presented themselves successively to its blows. The Tartars had found Russia divided against herself. 3. Even though Russia had wished to form a confederation, the sudden irruptions of an army entirely composed of horsemen did not leave her time. 4. In the tribes ruled by Batu, every man was a soldier; in Russia the nobles and citizens alone bore arms: the peasants, who formed the bulk of the population, allowed themselves to be stabbed or bound without resistance. 5. It was not by a weak nation that Russia was conquered. The Tartar-Mongols, under Genghis Khan, had filled the East with the glory of their name, and subdued nearly all Asia. They arrived, proud of their exploits, animated by the recollection of a hundred victories, and reinforced by numerous peoples whom they had vanquished, and hurried with them to the West. When the princes of Galitch, of Volhynia, and of Kiev arrived as fugitives in Poland and Hungary, Europe was terror-stricken. The Pope, whose support had been claimed by the Prince of Galitch, summoned Christendom to arms. Louis IX prepared for a crusade. Frederic II, as emperor, wrote to the sovereigns of the West: "This is the moment to open the eyes of body and soul now that the brave princes on whom we reckoned are dead or in slavery." The Tartars invaded Hungary, gave battle to the Poles in Liegnitz in Silesia, had their progress a long while arrested by the courageous defence of Olmutz in Moravia, by the Tcheque voievode Yaroslaff, and stopped finally, learning that a large army, commanded by the King of Bohemia and the dukes of Austria and Carinthia, was approaching. The news of the death of Oktai, second Emperor of all the Tartars, in China, recalled Batu from the West, and during the long march from Germany his army necessarily diminished in number. The Tartars were no longer in the vast plains of Asia and Eastern Europe, but in a broken hilly country, bristling with fortresses, defended by a population more dense and a chivalry more numerous than those in Russia.