The ignominious failure of the usurper Wang Mang to found a dynasty was too recent to encourage any one to take upon himself the heavy charge of administering the whole of the Han empire, and so the state was split up into three principalities, and the period is known from this fact as the Sankoue. One prince, a member of the late ruling family, held possession of Szchuen, which was called the principality of Chow. The southern provinces were governed by a general named Sunkiuen, and called Ou. The central and northern provinces, containing the greatest population and resources, formed the principality of Wei, subject to Tsowpi, the son of Tsow Tsow. A struggle for supremacy very soon began between these princes, and the balance of success gradually declared itself in favor of Wei. It would serve no useful purpose to enumerate the battles which marked this struggle, yet one deed of heroism deserves mention, the defense of Sinching by Changte, an officer of the Prince of Wei. The strength of the place was insignificant, and, after a siege of ninety days, several breaches had been made in the walls. In this strait Changte sent a message to the besieging general that he would surrender on the hundredth day if a cessation of hostilities were granted, "as it was a law among the princes of Wei that the governor of a place which held out for a hundred days and then surrendered, with no prospect of relief visible, should not be considered as guilty." The respite was short and it was granted. But the disappointment of the besieger, already counting on success, was great when a few days later he saw that the breaches had been repaired, that fresh defenses had been improvised, and that Sinching was in better condition than ever to withstand a siege. On sending to inquire the meaning of these preparations, Changte gave the following reply: "I am preparing my tomb and to bury myself in the ruins of Sinching." Of such gallantry and resource the internecine strife of the Sankoue period presents few instances, but the progress of the struggle steadily pointed in the direction of the triumph of Wei.

The Chow dynasty of the Later Hans was the first to succumb to the princes of Wei, and the combined resources of the two states were then directed against the southern principality of Ou. The supreme authority in Wei had before this passed from the family of Tsowpi to his best general, Ssemachow, who had the satisfaction of beginning his reign with the overthrow of the Chow dynasty. If he had earned out the wishes of his own commander, Tengai, by attacking Ou at once, and in the flush of his triumph over Chow, he might have completed his work at a stroke, for as Tengai wrote, "An army which has the reputation of victory flies from one success to another." But Ssemachow preferred a slower and surer mode of action, with the result that the conquest of Ou was put off for twenty years. Ssemachow died in A.D. 265, and his son Ssemachu founded the new dynasty of the Later Tsins under the name of Vouti, or the warrior prince.

The main object with Vouti was to add the Ou principality to his dominions, and the descendants of Sunkiuen thought it best to bend before the storm. They sent humble embassies to Loyang, expressing their loyalty and submission, but at the same time they made strenuous preparations to defend their independence. This double policy precipitated the collision it was intended to avert. Vouti paid more heed to the acts than the promises of his neighbor, and he ordered the invasion of his territory from two sides. He placed a large fleet of war junks on the Yangtsekiang to attack his opponent on the Tunting Lake. The campaign that ensued was decided before it began. The success of Vouti was morally certain from the beginning, and after his army had suffered several reverses Sunhow threw up the struggle and surrendered to his opponent. Thus was China again reunited for a short time under the dynasty of the Later Tsins. Having accomplished his main task, Vouti gave himself up to the pursuit of pleasure, and impaired the reputation he had gained among his somewhat severe fellow-countrymen by entertaining a theatrical company of five thousand female comedians, and by allowing himself to be driven in a car drawn by sheep through the palace grounds. Vouti lived about ten years after the unity of the empire was restored, and his son, Ssemachong, or Hweiti, became emperor on his death in A.D. 290. One of the great works of his reign was the bridging of the Hoangho at Mongtsin, at a point much lower down its course than is bridged at the present time.

The reign of Hweiti was marred by the ambitious vindictiveness of his wife, Kiachi, who murdered the principal minister and imprisoned the widow of the Emperor Vouti. The only good service she rendered the state was to discern in one of the palace eunuchs named Mongkwan a great general, and his achievements bear a strong resemblance to those of Narses, who was the only other great commander of that unfortunate class mentioned in history. Wherever Mongkwan commanded in person victory attended his efforts, but the defeats of the other generals of the Tsins neutralized his success. At this moment there was a recrudescence of Tartar activity which proved more fatal to the Chinese ruler than his many domestic enemies. Some of the Hiongnou tribes had retired in an easterly direction toward Manchuria when Panchow drove the main body westward, and among them, at the time of which we are speaking, a family named Lin had gained the foremost place. They possessed all the advantages of Chinese education, and had married several times into the Han family. Seeing the weakness of Hweiti these Lin chiefs took the title of Kings of Han, and wished to pose as the liberators of the country. Hweiti bent before the storm, and would have made an ignominious surrender but that death saved him the trouble.