Obviously tantricism arose as a result of the large-scale admission of the aboriginal peoples in brahmanical society. - Ram Sharan Sharma

For their riches the monasteries came to be coveted by the Turkish invaders. They became special targets of the invaders’ greed. The Turks killed a large number of Buddhist monks in Nalanda, although some of the monks managed to escape to Nepal and Tibet.

The most explicit statement of immigration into the Subcontinent.

People will be surprised to find that the V.H.P. has been unable to cite any ancient Sanskrit text in support of its claim that there has been an ancient Hindu belief in Ram Janma-sthãna at Ayodhya. Surely, if there were such a strong belief there would have been numerous Vaishnavite texts exhorting worshippers to visit the spot. The absence of any such reference makes it very dubious that the belief in Ram Janma-sthãna is of such respectable antiquity as is being made out. It is even doubtful if it is earlier than the late eighteenth century, as we shall see.