250 BC-Third Buddhist council

The Third Buddhist council was convened in about 250 BCE at Asokarama in Pataliputra, supposedly under the patronage of Emperor Ashoka. This is however disputed, as mention of the council never appears in the Edicts of Ashoka.

The traditional reason for convening the Third Buddhist Council is reported to have been to rid the Sangha of corruption and bogus monks who held heretical views. It was presided over by the elder monk Moggaliputta-Tissa and one thousand monks participated in the Council. The council is recognized and known to both the Theravada and Mahayana schools, though its importance is central only to the Theravada.^[1]

https://en.wikipedia.org/wiki/Third_Buddhist_council