Who destroyed the world's biggest buddhist Nalanda University ?
Historians said - Brahminists ✍️

Even after the Islamic invasions of India, Brahmanist bigotry and hatred for Buddhists was not subdued. According to Sharmasvamin, a Tibetan pilgrim who visited Bihar three decades after the invasion of Bakhtiaruddin Khilji in the 12th century, the biggest library at Nalanda was destroyed by Hindu mendicants who took advantage of the chaos produced by the invasion.
He says that “they (Hindus) performed a Yajna, a fire sacrifice, and threw living embers and ashes from the sacrifice into the Buddhist temples. This produced a great conflagration which consumed Ratnabodhi, the nine-storeyed library of the Nalanda University”.
Source - velivada.com

Historian - @tishasaroyan
youtu.be

The greatest blow to Buddhism came from Islamic invasion. When the hordes of Islamic armies marched to India, they met Buddhists on their way to India. In their language, the images are called “But” and “Butshikan” or being iconoclastic was part of their faith. Their attack on Buddhists was more vicious than their attack on Hindus.
The pages of history between 11 to 13 centuries are written with the blood of slain Buddhist monks. They destroyed the world-famous the Buddhist "University of Nalanda". In Buddhism, there is no group of hereditary teachers like Brahminism, Buddhism started disappearing from India after the massacre of Buddhist monks. This is an example of how truth is defeated. But now after 600 years, India is remembering the Buddha and without the teachings of the Buddha, the future of India is in trouble.
-Dr. Ambedkar (25 November 1956)
velivada.com

The destruction of ancient Buddhist sites - D.N Jha
caravanmagazine.in