Dharma-svāmin, the Tibetan scholar who visited Bihar in the thirteenth
century, tells us that the Buddhists had put an image of Śiva in front
of Buddha’s image so as to protect it from the wrath of non-Buddhists
From Jha's "Looking for a Hindu identity". Footnotes for it read [G. Roerich, Biography of Dharmasvāmin, Patna, 1959, p.64]
From the same book:
"A Tibetan tradition has it that the Kalacuri king Kar a (eleventh century) destroyed many Buddhist
temples and monasteries in Magadha; and the Tibetan text pag-sam-jon-zang refers to the burning of the library of Nalanda by some
“Hindu fanatics.”
"
Footnote for it says:
B.N.S. Yadava, op. cit., p.346. It has been generally held that
Bakhtiyar Khalji destroyed the university at Nalanda. D.R. Patil, however,
categorically states that it was destroyed by the Śaivas (Antiquarian
Remains of Bihar, Patna, 1963, p.304). This view has been discussed at
some length by R.S. Sharma and K.M. Shrimali (A Comprehensive History of
India, vol. IV, pt.2 [A.D. 985–1206], forthcoming, chapter XXV(b):
Buddhism, footnotes 79–82)
*****
Raksha seems to be right in saying that Hindus used the method of appropriation to win over rival religions.
Thus Benoytosh Bhattacharya in his Introduction to Buddhist
Esoterism. has come to the conclusion, "it is possible to declare. without
fear of contradiction, that the Buddhists were the first to introduce the
Tantras into their religion, and that the Hindus borrowed them from the
Buddhists in later times, and that it is idle to say that later Buddhism
was an outcome of Saivaism", (p.147)
-- Dr. Benoytosh Bhattacharya
http://www.dspace.cam.ac.uk/retrieve/63 ... _01_02.pdf**
Regarding Shankara's Advaita, it is well known that his grand teacher was greatly influenced by Nagarjuna's Madhyamika karika and Shankara himself studied under Buddhists for some time. So it is interesting that after everything he disparages Buddha as someone who deceived people by showing a heretic path. Most of Shankara's work is related to propagating Hindu caste system with the superiority of Brahmins (which he himself was). He was also a worshiper of Shiva. This could be an evidence of the method of appropriation.