This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Buddhism nearly disappears from India in the wake of a military campaign, not a doctrinal defeat. Around 1193 the Turkic general Bakhtiyar Khilji led a force into Bihar and burned Nalanda, the great monastic university and library that had anchored Buddhist scholarship for centuries, killing many of its monks and scholars. The neighboring monastic centers of Vikramashila and Odantapuri were destroyed in the same period, and by the thirteenth century the destruction had spread across most of the subcontinent, leaving only scattered pockets of practice in the Himalayas.
What ended was the institutional base itself. Buddhism in India had depended on its great monastic universities for its organized, textual life, unlike Hinduism's broad lay following or Islam's own growing mass support in some regions. Once Nalanda, Vikramashila and Odantapuri were gone, there was no comparable structure left to sustain an organized, mass Buddhist presence, and the tradition ceased to exist that way across nearly the whole subcontinent.
This is recorded here as a political and institutional destruction, the burning of specific universities by a specific military campaign, rather than smoothed into a vaguer story of decline. What it changed for Buddhism's spread was decisive: the land of the Buddha's own teaching career, from the Ganges plain onward, lost its own organized tradition for the better part of seven centuries, until a very different kind of event revived it.