Following the collapse of the Mauryans, the first emperor of the Shunga Empire (Pushyamitra Shunga) is believed to have stop promoting Buddhism and contributed to a resurgence of Hinduism that forced Buddhism outwards to Kashmir, Gandhara and Bactria. Buddhist scripture such as the "Asokavadana" account of the "Divyavadana" and ancient Tibetan historian Taranatha have written about persecution of Buddhists. Pushyamitra is said to have burned down Buddhist monasteries, destroyed stupas, massacred Buddhist monks and put rewards on their heads, but some consider these stories as probable exaggerations. The Shunga revolt was viewed as a persecution of Buddhists by Euthydemus. Demetrius, the son of Euthydemus, "invaded" the Indus Valley in 180 BC. Historians now suggest that the invasion was intended to show their support for the Mauryans and thus, the Indo-Greek Kingdom was established in 170 BC, in order to prevent the Shunga Dynasty from advancing into the Indus Valley.