Q:
A: There were several causes, but the primary cause was the widespread adoption of Hinduism between 400 CE and 1000 CE. Hinduism appealed to ordinary people because it included a relationship with an external deity and cultivated devotional practice, neither of which were offered by Buddhism. The Muslim conquest of India, beginning in the 12th century CE, eliminated the remaining outward symbols of Buddhism, such as stupas, and this resulted in the disappearance of Buddhism from virtually the entire subcontinent.