Decline of Buddhism in the Indian subcontinent
Buddhism, which originated in India, gradually dwindled and was replaced by approximately the 12th century. According to Lars Fogelin, this was "not a singular event, with a singular cause; it was a centuries-long process." The decline of Buddhism in the Indian subcontinent coincides with the spread of Islam in that part of the world, especially due to the Islamic invasions that occurred in the late 12th century. Another factor was invasions of north India by various groups such as Indo-Iranian Huns, Hephthalite Huns, Alchon Huns, Turco-Mongols, Arabs, and Persians, and subsequent Islamic destruction of Buddhist temples, shrines, and institutions, such as the Taxila and Nalanda universities, and religious persecutions perpetrated by Muslim invaders. Religious competition with other Indic religions and later Islam were also important factors. The Persecution by Alchon Huns in 5th century and subsequent destruction of Buddhist centres caused the decline of Buddhism in the northwestern regions of the Indian subcontinent. A similar process occurred in northeast, where Islamization of Bengal and demolitions of Nalanda, Vikramasila and Odantapuri by Muhammad bin Bakhtiyar Khalji, a general of the Delhi Sultanate are thought to have severely weakened the practice of Buddhism in East India where it previously received strong patronage