It is universally believed that the Mahasanghikas were the earliest seceder and the forerunners of the Mahayana. Around the 3^rd century B. C. Mahasanghikas has split up into 7 schools, among them the Caityakas and the Saila schools were the most prominent and had great influence in the south. Both of them paved the way for the growth of Mahayanism.

In the earlier years, the Mahsanghikas could not make much headway because of the strong opposition of the orthodox monks, the Sthaviravadins. They had to struggle hard to establish themselves in Magadha but they steadily gained in strength and became a powerful sect.

Mahsanghikas established centers at Pataliputra and Vesali and spread its network to both the North and the South. Therefore this school is not confined to Magadha but spread over the northern and western parts of India and had adherents scattered all over the country. The other branches of this sect were however concentrated in the south.

Although the Mahasanghika school extended their activities both towards the North and South, however, they gained more influence in the south particularly in the Guntur and Krishna districts where the popularity of the Caityakas and the Saila sub sects contributed much to their success.

The compilation of the Mahasanghikas was designated the Acariyavada as distinguished from the Theravada compiled at the First Council. It is the first book of the Vinaya-pitaka of the Lokottaravadins. According to it, the Buddhas are lokottara (supramundane) and are connected externally only with the worldly life. This concept of the Buddha contributed much to the growth of the Mahayana philosophy.

The only original work of the Mahasanghika sect available is the Mahavastu or the Mahavastuavadana, probably composed between the second century B.C. and the 4^th century A.D., it is the biography of the Buddha and gives us the history of the foundation of the Sangha and the first conversions. The languages used in these texts were partly in Sanskrit and partly in Prakit or mixed Indian dialect allied to Sanskrit.

The Mahasanghika adapted the existing rules of the Vinaya to their doctrine and introduced new ones. They did not recognize as the Abhidharma, which was compiled in the 3rd Council, the Parivana (appendix to the Vinaya, probably the composition of a Singhalese monk) parts of the Jataka and others. They therefore compiled afresh the texts of the Dhamma and the Vinaya and included those texts, canonized a number of sutras which they claimed to be the sayings of the Buddha, rejected certain portions of the canon which had been accepted in the First Buddhist Council. Thus arose a twofold division in the Buddhist Canon.

The Mahasanghikas claimed more orthodoxy than the Theravadins and believed that they have preserved more accurately the pitaka as settled by Mahakassapa in the First Council. Both schools had no difference of view regarding what constituted the most important portion of the Buddha's teachings such as the Four Noble Truths, the Eightfold Path, non-existence of the soul, the theory of Karma, the theory of paticca-samuppada, the gradual stages of spiritual advancement, the 37 Bodhipakkhiya dharmas etc. The schools differed in their Buddhalogical speculations and the corollaries.

The Mahasanghikas believed that Buddhas are supramundane (superhuman) and had no worldly attributes, the mortal being Sakya Gautama was required only for conforming to the worldly ways for the benefit of this world. Other important concepts created by the sect are:

1. The corollaries based on this belief are that Buddha is omnipotent, speaks truths only.
2. Buddha's physical body (rupa-kaya), life, energy and power are limitless, is always self-possessed and in samadhi.
3. Buddhas are supramundane, do not pass through the embryonic stages of ordinary beings, never experience feelings of lust etc.
4. For the benefit of all classes of sentient beings Buddhas are born of their own free will in any form of existence they choose.
5. It was for the enlightenment of worldly beings that the lokottara Buddha adopted the human form to enable people to imitate his examples and ultimately attain Buddhahood.
6. They are a class of beings who by passing through various trials and making immense self-sacrifices rose to higher stages of bodhisattvahood.
7. They could attain Buddhahood in the course of time.

The most important doctrine that resulted in this way is the theory of the Bodhisattvas. According to the Theravadins the aim of a Buddhist should be arahathood and not Buddhahood as it is exceedingly rare that a Buddha appears in the world. The Mahasanghikas believed otherwise, they do not look upon the position of an arahat as the highest stage of sanctification, their conception of the Buddha contributed to the growth of the later Trikaya theory in Mahayana (Dhamakaya, Nirmanakaya, Sambhogakaya). It was this point which brought about the schism between the Mahasanghikas and the Theravadins.

It was the Mahasanghikas who originated the worships of caitya and said that great merits could be acquired by circumabulating a stupa.

During the 2nd century after the Buddha's death, the Mahasanghika school split up into 7 schools: