What caused the decline of Nalanda University?

The decline of Nalanda University was a gradual process caused by multiple factors, but it culminated in a single, catastrophic event: its destruction by Turkish invaders.

1. The Primary Cause: The Attack by Bakhtiyar Khilji

The most direct and devastating cause was the sacking of the Nalanda Mahavihara around 1200 CE by the Turkic-Afghan military general Bakhtiyar Khilji and his forces.

Khilji, a general for the Ghurid dynasty, was leading raids in North India.

According to the Persian historian Minhaj-i-Siraj in his Tabaqat-i-Nasiri, Khilji's army mistook the fortified monastery for a fort.

They ransacked the university, killed the monks and scholars (who were mistaken for "shaven-headed Brahmins"), and, most famously, set fire to the great library, the Dharmagunj.

The library was so vast that it is said to have burned for several months, destroying an irreplaceable collection of manuscripts on philosophy, science, and religion.

2. Underlying Factors for its Decline:

Even before Khilji's attack, Nalanda was facing challenges:

• Decline of Buddhism: The influence of Buddhism in India, its parent religion, was already waning. It faced a strong intellectual and popular resurgence of Hinduism (particularly Advaita Vedanta) and a loss of public support.
• Loss of Royal Patronage: The Pala Empire, which had been the primary financial and political supporter of Nalanda, had weakened significantly. Without this royal patronage, the university struggled for funds and protection.
• Shift to Other Centers: Some patronage had also shifted to other centers of learning, like Vikramshila (which Khilji also destroyed).

The violent destruction by Bakhtiyar Khilji was the final, fatal blow. It not only destroyed the physical infrastructure but also dispersed its community of scholars, effectively ending an 800-year-old intellectual tradition and contributing significantly to the decline of Buddhism in its homeland.