Tai Yang Khan, king of the Christian tribe of Naimans, alarmed at the growing power of the young ruler, sent Alakush-Tekin, chief of the Onguts, or white Tatars, an invitation to join him against the ambitious Mongol. Alakush-Tekin immediately informed Chingiz of the Naimans’ intentions, assuring him at the same time of his own friendly feeling. Chingiz promptly marched against Tai Yang, who descended from the Altai to the foot of the Khanggai Mountains, attended by many allies, among whom was Tukta, king of the Merkits.362 In the battle which took place the Naimans were utterly routed. Among the prisoners who fell into the hands of the Mongols was Tatatungo, the chancellor of Tai Yang, who belonged to the UÏghur tribe, and tradition attributes to his influence the veneer of civilisation of the Mongols; and it is certain that Chingiz caused him to instruct his sons in the language, laws, and customs of the UÏghurs.363

Tai Yang Khan perished in this battle, while his son Guchluk fled by way of Bish Balik to the country of the Gur-Khan of Kara-Khitay.364 After wandering for some time and enduring great privations, he at length arrived at the court of the Gur-Khan (1208). He was hospitably received, and the Khan gave him his daughter in marriage; but the favours showered on him did not prevent his plotting to dethrone his benefactor. He obtained permission to enlist the remnants of the Naiman tribe, and thus collected a considerable force; then he entered into a league with Mohammad Shah of Khwarazm, and `Othman, prince of Samarkand, who, as we have seen above, were both vassals of the Gur-Khan. They arranged that they should attack their Gur-Khan suzerain simultaneously, the one from the east and the other from the west. The conditions determined on were that if Sultan Mohammad should be the first to gain a victory, Almaligh, Khotan, and Kashghar, which were in Guchluk’s hands, should be ceded to him; but if, on the other hand, Guchluk should win the initial success, Kara-Khitay, as far as Finaket, should be delivered over to him.365 Guchluk arrived before the Sultan, and was at first successful, but was afterwards defeated on his way to attack Balasaghun, and obliged to retreat. In the meantime the troops of Mohammad and `Othman had entered Kara-Khitay, and gained a victory over the Gur-Khan’s general, Tanigu, near the city of Taraz. Guchluk, taking advantage of this reverse, hurried back, surprised the Gur-Khan, and took him prisoner, A.H. 608 (1212). Two years later the Gur-Khan died, at a very advanced age. Guchluk, now firmly established on the throne of Kara-Khitay, reduced his new subjects to complete obedience. He was a cruel persecutor of Islam, being himself a Nestorian Christian until his marriage with the Gur-Khan’s daughter, when he became a Buddhist.366

Chingiz had been occupied since the overthrow of the Naimans with the conquest of China, and “though it was reserved for his grandson to complete the subjugation of the Celestial Empire,367 a great part of the northern provinces ... was added to the Mongol dominions during the great Khan’s own lifetime.”368

In 1218 he despatched an army 20,000 strong, under Noyan Chebe, to attack Guchluk Khan in Kashghar. Hearing of their approach, Guchluk fled, but was shortly afterwards overtaken in the mountains of Badakhshan and put to death. He was, as we have seen, a bigot, and especially intolerant in his dealings with Mohammedans. The Mongols proclaimed religious liberty, and thereby ensured for themselves the favour of the people.369

After the downfall of the Kara-Khitays the possessions of Mohammad of Khwarazm extended into the heart of Turkestan, with Samarkand as a capital. Those of Guchluk Khan were restricted to Kashghar, Khotan, and Yarkand.370

Chingiz’s relations with his powerful neighbour in Khwarazm were long of a peaceful and even friendly nature, but causes were at work which altered them radically.371 Abu-l-Ghazi states372 that the Caliph Nasir’s intense jealousy of the northern empire led him to adopt every means in his power to weaken it, and that he invited Chingiz to attack Sultan Mohammad. It is probable that this perfidious policy caused a coldness between the two potentates; but the immediate cause of rupture was an act for which the Khwaarazm Sultan was alone responsible. He cruelly slew, at Otrar, some Mohammedan traders who had incurred his animosity, in spite of the fact that they were travelling under Chingiz’s protection. The avalanches which descended on the habitable world in the twelfth century were thus set in motion by princes whose interest required that the vast forces controlled by Chingiz should remain pent up in their native steppes.

In A.H. 615 (1218) he set out for Otrar, determined to avenge the insult offered by Sultan Mohammad, and on his way was joined by large reinforcements of Karliks, UÏghur and other Mongol tribes, eager to share in the plunder of the West.373 On reaching that goal he divided his forces among his sons, and laid down for each the object of attack.

Ogday and Chaghatay were to reduce Otrar; Juji Khan was despatched in the direction of Jand; while two of his generals, with 5000 men, were sent to attack Finaket and Khojend. With the remainder of his forces Chingiz himself, accompanied by his son Tuli, set out for Bokhara,374 and arrived at that capital in A.H. 616 (1219), having carried all before him on his march. No sooner had he appeared than the garrison, 20,000 strong, fled towards Khwarazm, but were overtaken on the banks of the Oxus and cut to pieces by the Mongols sent in their pursuit. Meanwhile the shaykhs and mullas of Bokhara sallied forth and presented the keys of the town to Chingiz Khan, who made a formal entry, penetrated the courtyard of the principal mosque on horseback, and asked whether this fine building was Sultan Mohammad’s palace. On being told that it was God’s house he dismounted, and, ascending the pulpit, hurled the Koran beneath his horse’s feet. He next insisted that the inhabitants should deliver up their hidden treasures. Here his destroying hand would have been stayed had he not learnt that some remnants of Sultan Mohammad’s garrison were still in hiding. In order to compass their death he ordered the city, which was mainly built of wood, to be given to the flames. His behests were obeyed, and Bokhara for a time ceased to exist. Chingiz, however, caused it to be rebuilt.375

Meanwhile success had attended all his other army corps; and Otrar, Jand, and Khojend, together with many other towns, submitted to the Mongols. The sons and generals of Chingiz now joined the main body, and their united forces together marched on Samarkand. Before the end of the year A.H. 616 (1219) this great city, after a three days’ siege, fell. The garrison was put to the sword, and Samarkand was given over to reckless pillage.

It is not necessary here to record the story of the Mongol’s progress of conquest. Khwarazm soon succumbed, and Khorasan was overrun by his hordes. The Sultan himself took no active part in the hopeless effort to stay the advance of Chingiz, but fled across Khorasan376 to an island in the Caspian named Abasgun, not far from the modern Astarabad, where in A.H. 617 (1220) he died in utter destitution.377 A manful struggle to revive the glory of his house was made by Sultan Mohammad’s heroic son Jalal ud-Din, whose career forms one of the most exciting narratives in history.378 This last representative of the Khwarazm Shahs, after having boldly faced death on a hundred battlefields, was brutally murdered in A.H. 628 (1231) by a low-born Kurd.