The peace of Pienkiao was soon broken. The tribes again drew their forces to a head for the purpose of invading China, but before their plans were complete Taitsong anticipated them by marching into their territory at the head of a large army. Taken by surprise, the Tartars offered but a feeble resistance. Several of their khans surrendered, and at a general assembly Taitsong proclaimed his intention to govern them as Khan of their khans, or by the title of Tien Khan, which means Celestial Ruler. This was the first occasion on which a Chinese ruler formally took over the task of governing the nomad tribes and of treating their chiefs as his lieutenants. Down to the present day the Chinese emperor continues to govern the Mongol and other nomadic tribes under this very title, which the Russians have rendered as Bogdo Khan. The success of this policy was complete, for not only did it give tranquillity to the Chinese borders, but it greatly extended Chinese authority. Kashgaria was then, for the first time, formed into a province under the name of Lonugsi, and Lichitsi, one of the emperor's best generals, was appointed Warden of the Western Marches. Some of the most influential of Taitsong's advisers disapproved of this advanced policy, and attempted to thwart it, but in vain. Carried out with the vigor and consistency of Taitsong there cannot be two opinions about its wisdom and efficacy. During this reign the relations between China and two of its neighbors, Tibet and Corea, were greatly developed, and the increased intercourse was largely brought about by the instrumentality of war. The first envoys from Tibet, or, as it was then called, Toufan or Toupo, are reported to have reached the Chinese capital in the year 634. At that time the people of Tibet were rude and unlettered, and their chiefs were little better than savages. Buddhism had not taken that firm hold on the popular mind which it at present possesses, and the power of the lamas had not arisen in what is now the most priest-ridden country in the world. A chief, named the Sanpou--which means the brave lord--had, about the time of which we are speaking, made himself supreme throughout the country, and it was said that he had crossed the Himalaya and carried his victorious arms into Central India. Curiosity, or the desire to wed a Chinese princess, and thus to be placed on what may be termed a favored footing, induced the Sanpou to send his embassy to Singan; but although the envoys returned laden with presents, Taitsong declined to trust a princess of his family in a strange country and among an unknown people. The Sanpou chose to interpret this refusal as an insult to his dignity, and he declared war with China. But success did not attend his enterprise, for he was defeated in the only battle of the war, and glad to purchase peace by paying five thousand ounces of gold and acknowledging himself a Chinese vassal. The