Back to the history of Sz-ma Ts’ien one must return for the next harvest of Mongolia’s dragon-teeth. The Tung-hu, whose descendants are now the skin-clad Tunguses that live far to the north, even up to the Arctic Ocean, came down between 309 and 439 A.D. upon Manchuria. This occupation separated China from Corea, which, thus isolated, preserved for centuries the old Han dialect. The Tung-hu conquerors established a great kingdom extending from the Japan Sea to Turkestan. From 380 to 580 they ruled the northern kingdom of China proper. The leading place among those who composed their empire was held by the tribe of Juju, or Geougen, whose descendants are now the Finns. Subject to the Juju was a Mongol clan descended from the old southern Hiung-nu, who lived hard-by Mount Altai. They were blacksmiths and armorers for the Tung-hu army, and were called Turks. Their crescent power gradually supplanted that of their masters. In 480 this people appeared on the border of China. By 560 the Turkish Empire had become supreme in Central Asia. They pressed upon the nation of Avars on the Altai borderland of the steppe, until twenty thousand of these, refusing to submit, moved westward. Justinian received the envoys of the fugitives in 558. They offered to serve him, and threatened, if unaccepted, to attack his Eastern Empire. Anxious only to keep them away from his own domains, and indifferent as to which should survive, he sent them to attack his German enemies. The Avars, conquering a place in Europe, established a powerful nation between the Danube and the Elbe, biding their time till with the other barbarians they could descend to the spoil of Rome. After their rebellious vassals came the Turkish envoys, with richer presents to the Eastern Emperor Justin II, and more alarming menaces. The military alliance of the Turks was accepted and that of the Avars renounced. Kemarchus carried the ratification of Rome’s treaty to Mount Altai in Central Asia. For many years there was friendship between Mongol and Byzantine, mutual alliance and trade. In 618 the great T’ang Dynasty arose in China, whose fame is suggested in the fact that the only Cantonese word for a Chinese nationality is “Man of T’ang.” The energetic Li-shi-min subdued the Manchurian Tunguses, and in 630 a great battle broke the Turkish power. China once again was supreme from Corea to the borderland of Persia. During the T’ang Dynasty, Kashmir in India, and Anam were captured by the Chinese.