Analysis of information sources in references of the Wikipedia article "History of Tibet" in English language version.
The Tibetan records claim that some of their rulers, who were contemporaries of Dharmapala and Devapala, conquered the dominions of the Palas, and specifically, refer to Dharamapala as submitting to Tibetan supremacy. This is not, however, corroborated by any independent evidence, and we cannot say how far the claims can be regarded as historically true. It is not unlikely that Tibet exercised some political influence in Eastern India during the period A.D. 750-850, and the occasional reverses of the Pala rulers at the hands of the Pratiharas and the Rashtrakutas may be partly due to Tibetan aggression.