Mohammed Ghori had the Hindu temples of Ajmer demolished and ordered the construction of mosques and Quran schools on their ruins…He plundered Kanauj… - Muhammad bin Bakhtiyar Khalji

Khalji’s military exploits in the east also resulted in conversions to Islam. About the end of the twelfth or the beginning of the thirteenth century, he marched into Bihar and attacked the University centres of Nalanda, Vikramshila and Uddandapur, erecting a fortress at the site of Uddandapur or Odantapuri. The Buddhist monks in these places were massacred and the common people, deprived of their priests and teachers, turned some to Brahmanism and some to Islam. Buddhism did not die out immediately or completely in Bihar. But Bakhtiyar’s raid on Bihar did deliver a shattering blow to Buddhism and its lost followers were gained mainly by Islam.

Muhammad Bakhtiyar sweeping the town with the broom of devastation, completely demolished it, and making anew the city of Lakhnauti… his metropolis, ruled over Bengal… and strove to put in practice the ordinances of the Muhammadan religion… and for a period ruling over Bengal he engaged in demolishing the temples and building mosques.

…In the second year after this arrangement Muhammad Bakhtyar brought an army from Behar towards Lakhnauti and arrived at the town of Nudiya, with a small force; Nudiya is now in ruins. Rai Lakhmia (Lakhminia) the governor of that town… fled thence to Kamran, and property and booty beyond computation fell into the hands of the Muslims, and Muhammad Bakhtyar having destroyed the places of worship and idol temples of the infidels founded Mosques and Monasteries and schools and caused a metropolis to be built called by his own name, which now has the name of Gaur. There where was heard before The clamour and uproar of the heathen, Now there is heard resounding The shout of 'Allaho Akbar'.