The Kushan Empire conquered most of Northern India. The empire adopted war elephants when levying troops as they expanded into the Indian subcontinent.The Weilüe describes how the population of Eastern India rode elephants into battle, but currently they provide military service and taxes to the Yuezhi (Kushans). The Hou Hanshu additionally describes the Kushan as acquiring riches including elephants as part of their conquests. The emperor Kanishka assembled a great army from his subject nations, including elephants from India. He planned on attacking the Tarim Kingdoms, and sent a vanguard of Indian troops led by white elephants. However, when crossing the Pamir Mountains the elephants and horses in the vanguard were unwilling to advance. Kanishka is then said to have had a religious revelation and rejected violence.