The Mahasamghika school (`those Belonging to the Universal Sangha') represents one of the earliest systematic interpretations of Buddhist doctrine.  Very little material on the fraternity has survived and we can only piece together their doctrines from sources preserved mainly in Chinese. Although regarded as a non-Mahayana school the Mahasamghika had a view of the Buddha which looks characteristically  Mahayana. Indeed, what remains of the Mahasamghika canon incorporates elements of, and has been incorporated by, the Mahayana. An example of this is the Mahavastu sutra of the Mahasamghika which, like many  Mahayana  sutras, describes the stages through which a Bodhisattva passes on the way to enlightenment.
     The Mahasamghikas regarded the Buddha as supramundane, beyond all impurity and restriction. Although he is real, his human life was illusory and was lived for the benefit of sentient beings. Therefore his lives, even before his final miraculous human birth, transcended unenlightened knowledge and his human quest for enlightenment was illusory.  Because this is the case all the words he spoke were concerned with the transcendent and it is up to listeners to understand them rightly according to their capabilities. Unlike the Sthaviravadins (the elders) the  Mahasamghikas accepted five points put forward by a monk named Mahadeva who argued that arhats were still subject to nocturnal emissions as a result of erotic dreams; that, though spiritually enlightened, they were still subject to ignorance on worldly matters; that they were subject to doubt; that they could still acquire information from other people; and that when entering the enlightened state they may speak certain words, for example "dukkha!". These points, which represented a lowering in the status of an arhat, may also have been an attempt to re-present arhatship as an attainable goal.

The Mahasamghika school maintained the view of the majority of the Buddhist Sangha when it first divided from the Sthaviravadins either at the second Buddhist council at Vaisali, held about seventy years after the Buddha's death or, more likely, at a later meeting at Pataliputra in about 308BCE. Three possible reasons for this division have been advanced, based on accounts preserved by various later schools. One possible reason was a division over matters of doctrine which centres on Mahadeva's five points. Although Mahadeva's points were significant for future doctrinal development, they are unlikely to have been the cause for this early division since schisms (sanghabeda) generally resulted from differences in the vinaya, the disciplinary code. According to some sources, the Sthaviravadins divided from the  Mahasamghika in order to reestablish adherence to the vinaya after it had become lax.  Mahasamghika sources however record that the Sthaviravadin elders were attempting to introduce minor rules which had not been laid down at the original vinaya recitation at the first Council and were thereby straying unnecessarily from the tradition. This interpretation is backed up by the fact that the  Mahasamghika vinaya, which has survived, is thought to be very early and is indeed the shortest surviving version of the vinaya.
     We know that the Mahàsàüghikas later subdivided into two fraternities; the Ekavyavhàrika in the north and the Caitra in the south, although sources are insufficient to provide details of these developments.

There is no textual or inscriptional evidence to indicate that the school had a distinct symbol system.

The Mahasamghika school and much of its canon was destroyed during the Muslim invasion of Northern India in the twelfth century. However, the influence of the  Mahasamghika survives through the admission of its sutras to the Mahayana canon, particularly in its Chinese recension.

The school was very strong in Magadha, at Pataliputra, and there is inscriptional evidence of its presence in Mathura from 120 BCE. At a later date it established a centre in Southern India in the Guntur district.