324 THE MEDIAEVAL KINGDOMS OF THE NORTH Between 665 and 715 the government of China was unable to interfere effectually in the affairs of the coun- tries between the Jaxartes (Syr Darya) and the Indus, since the southern route to the west through Kashgaria had been closed by the Tibetans, and the roads over the Hindu Rush were blocked by the conquests of Kotaiba, the Arab general. The accession of the Emperor Hiuen-tsong in 713 marks a revival of Chinese activity; and determined efforts were made by means both of diplomacy and arms to keep open the Pamir passes and to check the ambi- tion of the Arabs and Tibetans, who sometimes com- bined. In 719, Samarkand and other kingdoms invoked the aid of China against the armies of Islam, while the Arab leaders sought to obtain the co-operation of the minor states on 'the Indian borderland. The chiefs of Udyana (Suwat), Khottal (west of Badakshan), and Chitral, having refused to listen to Moslem blandish- ments, were rewarded by the Emperor of China with letters patent conferring on each the title of king, and a similar honour was bestowed upon the rulers of Yasin (Little Po-lu), Zabulistan (Ghazni), Kapisa, and Kash- mir, received investiture as king from the emperor in kingdoms, so as to form an effective barrier against both Arabs and Tibetans. Chandrapida, King of Kash- mir, received investiture as king from the emperor in 720, and his brother Muktapida-Lalitaditya was sim- ilarly honoured in 733. A few years later in 744 and 747 Chinese influence had been so far extended that the emperor granted
