A second Buddhist council, convened by King Kalasoka, takes place at Vaishali in about 383 BCE, during which the advocates of certain relaxations in the vinaya rules are condemned.

Traditions regarding the Second Council are confusing and ambiguous, but it is agreed that the overall result was the first schism in the Sangha, between the Sthaviras and the Mahāsāṃghikas, although the cause of the split is not universally agreed upon.

The origins of the Mahāsāṃghika sect of Buddhism are still extremely uncertain, and the subject of debate among scholars.

One reason for the interest in the origins of the Mahāsāṃghika school is that their Vinaya recension appears in several ways to represent an older redaction overall.

Many scholars also look to the Mahāsāṃghika branch for the initial development of Mahāyāna Buddhism.