The so called Second Buddhist council resulted in the first schism in the Sangha. Modern scholars believe that this was probably caused when a group of reformists called Sthaviras ("elders") sought to modify the Vinaya (monastic rule), and this caused a split with the conservatives who rejected this change, they were called Mahāsāṃghikas. While most scholars accept that this happened at some point, there is no agreement on the dating, especially if it dates to before or after the reign of Ashoka.