The death of the Caliph Muktadi, which occurred about the same period, induced Berkiyāruk to go to Baghdād, where he confirmed Mostadhhir as the new Caliph, and was in return hailed by him as Sultan of the empire. He enjoyed that dignity for eleven years,[297] but his reign was a perpetual war in which his nearest relatives and all the great nobles of the state were engaged. His usual residence was Baghdād. His brother Mohammad ruled over Āzerbāyjān, while Sanjar established a kingdom in Khorāsān and Transoxiana, whence he extended his conquests over the fallen princes of Ghazna, compelling them to pay him tribute. Berkiyāruk, who appears to have had an excellent disposition, and to have been wanting neither in courage nor conduct, died on a journey from Isfahān to Baghdād,[298] A.H. 498 (1104). He felt his end approaching, and before he expired made his army take the oath of fidelity to his son Melik Shāh II. The young prince was, however, unable to resist his uncle Mohammad, who seized Baghdād treacherously and took him prisoner, A.H. 498 (1104). The reign of Mohammad, which lasted thirteen years, was remarkable only for continual civil disturbances, and for the wars which his generals carried on in Syria against the European armies engaged in their crusade to recover the sacred city of Jerusalem and the Holy Land from the Mohammedans. He died at Isfahān in A.H. 511 (1117), and was nominally succeeded by his son Mahmūd, who was almost immediately reduced by his uncle Sanjar to the condition of a dependant.[299] Sanjar, who had been governor of Khorāsān and its dependencies for the past twenty years, now became Sultan, and as such enjoyed a reign of no less than forty years, A.H. 511–552 (1117–1157). We must now turn our attention to Transoxiana and the East, where important events were passing. CHAPTER XIX SULTAN SANJAR AND THE KARA-KHITĀYS The country of Khwārazm[300] was one of the first conquests of the Seljūks. On becoming masters of Khorāsān, the `Irāks, Persia, and Syria, they chose men from among their Turkish slaves whom they placed in charge of the various provinces. The governor thus set over Khwārazm was named Balkategin, who was _Tasht-dār_, or Grand Ewer-bearer,[301] to Sultan Melik Shāh, who exercised paramount authority in that country. He had under him a Turkish slave whom he had purchased, named Nūshtegin, who by his conduct at his master’s court was in such esteem that on the death of Balkategin[302] he succeeded to the government of Khwārazm. He became even more powerful than his lord, but, though he is regarded as the first of the dynasty of Khwārazm-Shāhs, he remained loyal to the Seljūks. He bestowed great care in the education of his son Kutb ed-Dīn Mohammad, who succeeded him in A.H. 490 (1097) with the additional title of _Khwārazm-Shāh_, or emperor of Khwārazm. He was a great patron of letters, and made himself generally beloved in his province.