Into this mixed population of Christianized Slavs and more or less Christianized and Slavized Mongols burst Jenghiz Khan with his great hordes of pure Mongols. All southern Russia, Poland, and Hungary collapsed before them, and in southern Russia the rule of the Mongol persisted for centuries, in fact the Golden Horde of Tatars retained control of the Crimea down to 1783. Many of these later Tatars had accepted Islam, but entire groups of them have retained their Asiatic speech and to this day profess the Mohammedan religion. The most lasting result of these Mongol invasions was that southern Poland and all the countries east and north of the Carpathians, including Rumania and the Ukraine, were saturated anew with Tatar blood, and, in dealing with these populations and with the new nations founded among them, this fact must not be forgotten. The conflict between the East and the West--Europe and Asia--has thus lasted for centuries, in fact it goes back to the Persian Wars and the long and doubtful duel between Rome and Parthia along the eastern boundary of Syria. As we have already said, the Saracens had torn away many of the provinces of the Eastern Empire, and the Crusades, for a moment, had rolled back the East, but the event was not decided until the Seljukian and Osmanli Turks accepted Islam. If these Turks had remained heathen they might have invaded and conquered Asia Minor and the Balkan States, just as their cousins, the Tartars, had subjected vast territories north of the Black Sea, but they could not have held their conquests permanently unless they had been able to incorporate the beaten natives into their own ranks through the proselytizing power of Islam. Even in Roman times the Greek world had been steadily losing, first its Nordic blood and then later the blood of its Nordicized European population, and it became in its declining years increasingly Asiatic until the final fall of Constantinople in 1453. Byzantium once fallen, the Turks advanced unchecked, conquering the Alpine Slav kingdoms of the Balkans and menacing Christendom itself. In these age-long conflicts between Asia and Europe the Crusades seem but an episode, although tragically wasteful of Nordic stock. The Nordic Frankish nobility of western Europe squandered its blood for two hundred years on the desert sands of Syria and left no ethnic trace behind, save, perhaps, some doubtful blond remnants in northern Syria and Edessa.