According to the Tibetan account no more monasteries were built for seven reigns.  The eighth king built two, one on the celebrated Gosirsha or Gosringa mountain.  In the eleventh reign after Vijayasambhava, more chaityas and viharas were built in connection with the introduction of the silkworm industry.  Subsequently, but without any clear indication of date, the introduction of the Mahasanghika and Sarvastivadin schools is mentioned.

The Tibetan annals also mention several persecutions of Buddhism in Khotan as a result of which the monks fled to Tibet and Bruzha.  Their chronology is confused but seems to make these troubles coincide with a persecution in Tibet, presumably that of Lang-dar-ma.  If so, the persecution in Khotan must have been due to the early attacks of Mohammedans which preceded the final conquest in about 1000 A.D.[521]

Neither the statements of the Chinese annalists about Central Asia nor its own traditions prove that Buddhism flourished there before the Christian era.  But they do not disprove it and even if the dream of the Emperor Ming-Ti and the consequent embassy are dismissed as legends, it is admitted that Buddhism penetrated to China by land not later than the early decades of that era.  It must therefore have been known in Central Asia previously and perhaps Khotan was the place where it first flourished.

It is fairly certain that about 160 B.C. the Yueh-chih moved westwards and settled in the lands of the Oxus after ejecting the Sakas, but like many warlike nomads they may have oscillated between the east and west, recoiling if they struck against a powerful adversary in either quarter.  Le Coq has put forward an interesting theory of their origin.  It is that they were one of the tribes known as Scythians in Europe and at an unknown period moved eastwards from southern Russia, perhaps leaving traces of their presence in the monuments still existing in the district of Minussinsk.  He also identifies them with the red-haired, blue-eyed people of the Chotscho frescoes and the speakers of the Tokharian language.  But these interesting hypotheses cannot be regarded as proved.  It is, however, certain that the Yueh-chih invaded India,[522] founded the Kushan Empire and were intimately connected (especially in the person of their great king Kanishka) with Gandharan art and the form of Buddhism which finds expression in it.  Now the Chinese pilgrim Fa-Hsien (c. 400) found the Hinayana prevalent in Shan-shan, Kucha, Kashgar, Osh, Udyana and Gandhara.  Hsuan Chuang also notes its presence in Balkh, Bamian, and Persia.  Both notice that the Mahayana was predominant in Khotan though not to the exclusion of the other school.  It would appear that in modern language the North-West Frontier province of India, Afghanistan, Badakshan (with small adjoining states), the Pamir regions and the Tarim basin all accepted Gandharan Buddhism and at one time formed part of the Kushan Empire.