Buddhism enjoyed promotion from power until the end of the reign Harshavardhana (8th A.D.) when royal patronage ended. This marked the beginning of a decay that extended until the Muslim invasions in the 13th century. Although Hindu scholars attribute the progressive decay to the divergences between sects and the appearance of tantric deviated conducts in monasteries, Hinduism, and most particularly, Brahmanism (a strict social organization on the basis of some religious ideas) tried to dilute Buddhism by presenting it as a kind of Hinduism. Thus, from the 7th century Buddha was included in the list of Avataras of Vishnu. The Muslim invasions in the 13th century brought the destruction of Buddhist Universities and the killings of Buddhist monks. Again, it is common for Hindu scholars to put the full blame on Muslims, but it is also a fact that there was a certain connivance of the Brahmin class at the local levels of administration, where they retained their privileges, with the new Muslim rulers. Moreover, the formation of Buddhist monks was conducted through rigorous training and therefore, they were less easily replaced than Brahmin priests ready-made by birth. Many Buddhist lay worshipers were driven to Islam by persecution. Evidently, the tolerant spirit of the Ashoka reign had long passed away.
