Buddhism in India was introduced by Siddhartha Gautama (ca. 563-483 B.C.), a prince from the small Shakya Kingdom in the foothills of the Himalayas in Nepal. Though brought up amidst lavishness, the prince left his home as a religious beggar, in order to find the meaning of existence. At first, he followed the path of strict penance but later realised that self-torture was weakening his mind rather than advancing him towards enlightenment. Then he adopted a milder style of renunciation and concentrated on superior meditation procedures. Ultimately, by continuous meditation under the Bodhi tree in Gaya, he attained an insight into the mystery of existence. His knowledge is precisely expressed as the Four Noble Truths: life is filled with suffering; the source of suffering is desire; the end of desire leads to the end of suffering; and discipline and meditation can end desire. Gautama, now known as the Buddha, spent the rest of his life traveling around northeast India, propagating his knowledge. He died at eighty, leaving a flourishing monastic order and a dedicated community to continue his work. Within the 7th century B.C., Buddhism has become the largest religion in the world, having spread throughout the Mauryan Empire and the East and Southeast Asia. Buddhism takes as its goal the escape from suffering and the cycle of rebirth and the attainment of Nirvana and emphasises meditation and the observance of moral precepts.

The Buddha, however did not appoint a successor, and asked his followers to work for individual salvation. The teachings of the Buddha survived only in oral traditions. The Sangha held a number of Buddhist Councils in order to reach consensus on matters of Buddhist doctrine and practice. According to the scriptures, a monk by the name of Mahakasyapa presided over the first Buddhist Council held at Rajgir (a city and a notified area in Nalanda district in Bihar). Its function was to enumerate and agree on the Buddha`s actual teachings and on monastic discipline.

The Second Buddhist Council is believed to have taken place at Vaishali (an ancient city, the capital of the Licchavis and the Vajjian Confederacy, presently considered as Vaishali district in Bihar). Its function was to deal with disputed monastic practices like the use of money, the drinking of palm wine, and other irregularities; the council declared these practices illicit.

What is commonly called the Third Buddhist Council was held at Pataliputra (present-day Patna) and was supposedly called by Emperor Ashoka in the 3rd century B.C. Organised by the monk Moggaliputta Tissa, it was held in order to rid the sangha of the large number of monks who had joined the order because of its royal patronage.

What is often called the Fourth Buddhist Council is usually believed to have been held under the patronage of emperor Kanishka at Jalandhar. It is generally believed to have been a council of the Sarvastivada school.

Following the Buddha`s passing away, India witnessed many philosophical movements emerging within Buddhism. The first of these were the various Early Buddhist Schools (including Theravada). Later, Mahayana Buddhism and Vajrayana Buddhism arose.

Buddhism in India witnessed a colossal impetus in its initial stages, with the stronghold of the Mauryan dynasty and Emperor Ashoka occupying centre-stage. The Mauryan Empire scaled peak heights at the time of emperor Ashoka, who himself converted to Buddhism after the legendary Kalinga War. This heralded a long period of solidity under the Buddhist emperor. The power of the empire was immense-ambassadors were sent to other countries to propagate Buddhism. During the 1st-3rd centuries, the Kushan Empire, under the able leadership of emperor Kanishka, were also responsible for the spread of Buddhism in other parts of Asia, and not only India. He hugely encouraged Buddhism, and it was during Kanishka`s reign that Buddha was first represented as a human form. Indian shramanas (a wandering monk in specific ascetic traditions of ancient India, including Jainism, Buddhism and Ajivika religion) can also be held responsible to have propagated Buddhism in various regions; they were also referred to as dharma masters.

Buddhism in India also proliferated with the patronisation of the Buddhist monasteries by Indian sovereigns and merchants, who erected stupas over the relics of the Buddha. Archaeological evidences since 1840 (like the Nalanda complex in Bihar) have revealed a massive impact of Buddhist art, iconography, and architecture in India. Astonishingly, by the 13th century, after the Turkish invasion, Buddhism survived mainly in Bhutan and Sikkim, probably due to shift of royal patronage towards Hinduism. Buddhism in India again staged a comeback in the 20th century through European sponsorship and the Mahabodhi Society was founded in 1891. In 1956, Bhimrao Ramji Ambedkar, leader of the Untouchable wing within the Congress advocated Buddhism as a means to evade the caste system of Hinduism. By the early 1990s, there were more than 5 million Buddhists in Maharashtra. These along with the Buddhist populace in hill areas of northeast India and high Himalayan valleys (Ladakh District in Jammu and Kashmir, Himachal Pradesh, and northern Uttar Pradesh), as well as the entry of Tibetan Buddhist refugees who fled from Tibet with the Dalai Lama in 1959 and thereafter, raised the number of Buddhists in India to 6.4 million by 1991.

There are certain forms of Buddhism in India. That practiced by the Himalayan communities and Tibetan refugees are part of the Vajrayana, or "Way of the Lightning Bolt", that developed after the 7th century A.D. as part of Mahayana Buddhism. This form emphasises the intervention of the enlightened beings, which remain in this world to assist others on the path. A majority of the other Buddhists in India follow Theravada Buddhism, the "Doctrine of the Elders", which has its origin in the Sri Lankan and Burmese traditions as well as the scriptures in the Pali language. Filled with many legends, these scriptures stress a more human Buddha and an autonomous path towards illumination for everyone.

Buddhism in India has also affected other religions, especially in the concept of the enlightened master. For instance, one of the primary Hindu orders traces its origin to the teacher Shankara, believed by many devotees to have lived hundreds of years earlier. A different kind of renunciation appears in the cult of Sai Baba, whose two notable pioneers are Sai Baba (died 1918) and Satya Sai Baba (born in 1926). This cult mingles various meditation and devotional techniques along with advocating a humble life.