The name Theravāda comes from the ancestral Sthāvirīya, one of the early Buddhist schools, from which the Theravadins claim descent. After unsuccessfully trying to modify the Vinaya, a small group of "elderly members", i.e. sthaviras, broke away from the majority Mahāsāṃghika during the Second Buddhist council, giving rise to the Sthavira sect.[1] According to its own accounts, the Theravāda school is fundamentally derived from the Vibhajjavāda "doctrine of analysis" grouping,[2] which was a division of the Sthāvirīya.
Theravadin accounts of its own origins mention that it received the teachings that were agreed upon during the putative Third Buddhist council under the patronage of the Indian Emperor Ashoka around 250 BCE. These teachings were known as the Vibhajjavada.[3] Emperor Ashoka is supposed to have assisted in purifying the sangha by expelling monks who failed to agree to the terms of Third Council.[4] Later, the Vibhajjavādins in turn is said to have split into four groups: the Mahīśāsaka, Kāśyapīya, Dharmaguptaka, and the Tāmraparṇīya.