In the era of the Buddha, India was regarded as a pioneer in many fields. India had an economic surplus, political stability and more importantly, a history of spiritual and intellectual innovation. India was viewed as a superpower similar to 21st century America. Buddhism was received with open hearts in other countries in Asia because of its origin in India.
Then why such a formidable culture lost in India?
Before the birth of the Buddha, Indian society had become self-centered (the intellectual class) and ritualistic (the masses). Buddhism provided a new organized form of religious Sangha, which preached a simple message of compassion in Päli, the language of laypeople. This ease and simplicity helped the extensive spread of Buddhism.
Causes of decline:
The decline of Buddhism has been attributed to various factors, especially the regionalisation of India after the end of the Gupta empire (320-650 CE), which lead to a competition with Hinduism and Jainism and the loss of patronage and donations; and the conquest and subsequent persecutions by Huns, Turks and Persians.
Patronage and religious dynamics:
Loss of patronage and donations:
In ancient India, regardless of the religious beliefs of their kings, states usually treated all the important sects relatively even-handedly. This consisted of building monasteries and religious monuments, donating property such as the income of villages for the support of monks, and exempting donated property from taxation. Donations were most often made by private persons such as wealthy merchants and female relatives of the royal family, but there were periods when the state also gave its support and protection. In the case of Buddhism, this support was particularly important because of its high level of organisation and the reliance of monks on donations from the laity. State patronage of Buddhism took the form of land grant foundations.
Buddhism’s distinctiveness diminished with the rise of Hindu sects. Though Mahayana writers were quite critical of Hinduism, the devotional cults of Mahayana Buddhism and Hinduism likely seemed quite similar to laity, and the developing Tantrism of both religions were also similar. Buddhist ideas, and even the Buddha himself, were absorbed and adapted into orthodox Hindu thought, while the differences between the two systems of thought were emphasized.
According to some scholars such as Lars Fogelin, the decline of Buddhism may be related to economic reasons, wherein the Buddhist monasteries with large land grants focussed on non-material pursuits, self-isolation of the monasteries, loss in internal discipline in the sangha, and a failure to efficiently operate the land they owned. With the growing support for Hindusim and Jainism, Buddhist monasteries also gradually lost control of land revenue.
Reform in Hinduism:
Buddhism had dealt a heavy blow to Brahminical faith. Threatened with extinction, Hinduism started to re-organize itself. Attempts were now made to give up the complex system of rites and rituals and make Hinduism simple and attractive. The Hindus even came to accept the Buddha as a Hindu incarnation and accepted the principle of non-violence. This helped revive Hinduism and made it popular again. This took away the fragrance out of the flower of Buddhism. The decline of Buddhism became inevitable.
Lose of Royal Patronage:
In course of time Buddhism came to lose royal patronage. No king, worthy of note, came forward to sponsor Buddhism after Asoka, Kaniska and Harsavardhan. Royal patronage works magically for the spread of any faith. Absence of any such patronage for Buddhism came to pave the way for its decline in the end.
Emergence of Rajputs:
Emergence of the Rajputs became an important reason for the decline of Buddhism. Kings of such dynasties as Bundela, Chahamana, Chauhan, Rathore etc. were militant rulers and loved warfare. They could not tolerate the Buddhists for their message of non-violence. The Buddhists feared persecution from these Rajput rulers and fled from India. Buddhism became weaker and faced decline.
Patronage of Brahmanism:
In course of time there was the rise of the Brahminical faith once again. Pushyamitra Sunga, the Brahmin commander of the last Maurya ruler Vrihadratha, assassinated the king and founded the Sunga dynasty replacing the Maurya dynasty.
Role of Hindu Preachers:
Harsavardhan drove away the Brahmins from the religious council held at Kanauj. These Brahmins, under Kumarila Bhatta, fled to the Deccan. Under Bhatta’s leadership, Brahmanism staged a come-back. Adi Sankaracharya also revived and strengthened Hinduism. He defeated Buddhist scholars in religious discourses which were held in many places in course of his tour of the whole of India.
Wars and persecution:
Chinese scholars travelling through the region between the 5th and 8th centuries, such as Faxian, Xuanzang, Yijing, Hui-sheng, and Sung-Yun, began to speak of a decline of the Buddhist Sangha in the north-west parts of Indian subcontinent, especially in the wake of the Hun invasion from central Asia. Xuanzang wrote that numerous monasteries in north-western India had been reduced to ruins by the Huns.
Mihirakula who ruled from 515 CE in north-western region (modern Afghanistan, Pakistan and north India), suppressed Buddhism as well. He did this by destroying monasteries as far away as modern-day Allahabad.
In the Gangetic plains, Orissa, north-east and the southern regions of India, Buddhism survived through the early centuries of the 2nd millennium CE. According to William Johnston, hundreds of Buddhist monasteries and shrines were destroyed, Buddhist texts were burnt by the Muslim armies, monks and nuns killed during the 12th and 13th centuries in the Gangetic plains region. The Islamic invasion plundered wealth and destroyed Buddhist images:
From 986 CE, the Muslim Turks started raiding northwest India from Afghanistan, plundering western India early in the eleventh century. Force conversions to Islam were made, and Buddhist images smashed, due to the Islamic dislike of idolarty. Indeed in India, the Islamic term for an ‘idol’ became ‘budd’.— Peter Harvey, An Introduction to Buddhism
The north-west parts of South Asia fell to Islamic control, and the consequent take over of land holdings of Buddhist monasteries removed one source of necessary support for the Buddhists, while the economic upheaval and new taxes on laity sapped the laity support of Buddhist monks.
In the north-western parts of medieval India, the Himalayan regions, as well regions bordering central Asia, Buddhism once facilitated trade relations, states Lars Fogelin. With the Islamic invasion and expansion, and central Asians adopting Islam, the trade route-derived financial support sources and the economic foundations of Buddhist monasteries declined, on which the survival and growth of Buddhism was based. The arrival of Islam removed the royal patronage to the monastic tradition of Buddhism, and the replacement of Buddhists in long-distance trade by the Muslims eroded the related sources of patronage.
Islamic invasion and rule:
Muhammad Bin Bakhtiyar Khilji:
Vikramashila was destroyed by the forces of Muhammad bin Bakhtiyar Khilji around 1200. Many Buddhist monks fled to Nepal, Tibet, and South India to avoid the consequences of war. Tibetan pilgrim Chöjepal had to flee advancing Muslim troops multiple times, as they were sacking Buddhist sites.
Fall of Pala Dynasty by Muslim Invaders:
A major empire to support Buddhism, the Pala dynasty, fell in the 12th century, and Muslim invaders destroyed monasteries and monuments. According to Randall Collins, Buddhism was already declining in India by the 12th century, but with the pillage by Muslim invaders it nearly became extinct in India in the 1200s. In the 13th century, states Craig Lockard, Buddhist monks in India escaped to Tibet to escape Islamic persecution; while the monks in western India, states Peter Harvey, escaped persecution by moving to south Indian Hindu kingdoms that were able to resist the Muslim power.
Conquest of Turk Shah:
Brief Muslim accounts and the one eye witness account of Dharmasmavim in wake of the conquest during the 1230s talks about abandoned viharas being used as camps by the Turukshahs. Later historical traditions such as Taranathas are mixed with legendary materials and summarised as “the Turukshah conquered the whole of Magadha and destroyed many monasteries and did much damage at Nalanda, such that many monks fled abroad” thereby bringing about a demise of Buddhism with their destruction of the Viharas.