His colleagues induced him to leave the country for decency's sake and peace was restored but subsequently, after Chapaṭa's death, the remaining three disciples[154] fell out on questions of discipline rather than doctrine and founded three factions, which can hardly be called schools, although they refused to keep the Uposatha days together. The light of religion shone brightest at Pagan early in the thirteenth century while these three brethren were alive and the Sâsanavaṃsa states that at least three Arhats lived in the city. But the power of Pagan collapsed under attacks from both Chinese and Shans at the end of the century and the last king became a monk under the compulsion of Shan chiefs. The deserted city appears to have lost its importance as a religious centre, for the ecclesiastical chronicles shift the scene elsewhere. The two Shan states which arose from the ruin of Pagan, namely Panya (Vijayapura) and Sagaing (Jeyyapura), encouraged religion and learning. Their existence probably explains the claim made in Siamese inscriptions of about 1300 that the territory of Siam extended to Haṃsavatî or Pegu and this contact of Burma and Siam was of great importance for it must be the origin of Pali Buddhism in Siam which otherwise remains unexplained. After the fall of the two Shan states in 1364, Ava (or Ratnapura) which was founded in the same year gradually became the religious centre of Upper Burma and remained so during several centuries. But it did not at first supersede older towns inasmuch as the loss of political independence did not always involve the destruction of monasteries. Buddhism also flourished in Pegu and the Talaing country where the vicissitudes of the northern kingdoms did not affect its fortunes. Anawrata had transported the most eminent Theras of Thaton to Pagan and the old Talaing school probably suffered temporarily. Somewhat later we hear that the Sinhalese school was introduced into these regions by Sâriputta[155], who had been ordained at Pagan. About the same time two Theras of Martaban, preceptors of the Queen, visited Ceylon and on returning to their own land after being ordained at the Mahâvihâra considered themselves superior to other monks. But the old Burmese school continued to exist. Not much literature was produced in the south. Sâriputta was the author of a Dhammathat or code, the first of a long series of law books based upon Manu. Somewhat later Mahâyasa of Thaton (_c._ 1370) wrote several grammatical works.