It is clear that, though the Hinayanist church was predominant throughout the history of the island, there were up to the twelfth century heretical sects called Vaitulya or Vetulyaka and Vâjira which though hardly rivals of orthodoxy were a thorn in its side. A party at the Abhayagiri monastery were favourably disposed to the Vaitulya sect which, though often suppressed, recovered and reappeared, being apparently reinforced from India. This need not mean from southern India, for Ceylon had regular intercourse with the north and perhaps the Vaitulyas were Mahayanists from Bengal. The Nikâya-Sangrahawa also mentions that in the ninth century there was a sect called Nîlapatadarśana,[106] who wore blue robes and preached indulgence in wine and love. They were possibly Tantrists from the north but were persecuted in southern India and never influential in Ceylon. The Mahâvaṃsa is inclined to minimize the importance of all sects compared with the Mahâvihâra, but the picture given by the Nikâya-Sangrahawa may be more correct. It says that the Vaitulyas, described as infidel Brahmans who had composed a Piṭaka of their own, made four attempts to obtain a footing at the Abhayagiri monastery.[107] In the ninth century it represents king Matvalasen as having to fly because he had embraced the false doctrine of the Vâjiras. These are mentioned in another passage in connection with the Vaitulyas: they are said to have composed the Gûḍha Vinaya[108] and many Tantras. They perhaps were connected with the Vajrayâna, a phase of Tantric Buddhism. But a few years later king Mungayinsen set the church in order. He recognized the three orthodox schools or nikâyas called Theriya, Dhammaruci and Sâgaliya but proscribed the others and set guards on the coast to prevent the importation of heresy. Nevertheless the Vâjiriya and Vaitulya doctrines were secretly practised. An inscription in Sanskrit found at the Jetavana and attributed to the ninth century[109] records the foundation of a Vihâra for a hundred resident monks, 25 from each of the four nikâyas, which it appears to regard as equivalent. But in 1165 the great Parâkrama Bâhu held a synod to restore unity in the church. As a result, all Nikâyas (even the Dhammaruci) which did not conform to the Mahâvihâra were suppressed[110] and we hear no more of the Vaitulyas and Vâjiriyas. Thus there was once a Mahayanist faction in Ceylon, but it was recruited from abroad, intermittent in activity and was finally defeated, whereas the Hinayanist tradition was national and continuous.