secular topics of higher education (such as medicine, logic and grammar). The influence of the Gupta style of Buddhist art spread along with the faith from south-east Asia to China. During this period, Chinese pilgrims also visited India to study Buddhism. One of these pilgrims was Faxian, who visited India during the reign of the Gupta emperor Chandragupta II in 405, and commented on the prosperity and mild administration of the Gupta empire. Another Chinese traveler who reached India after the end of the Guptas in the 7th century was Xuanzang. He reported in his travels across India that Buddhism was popular in Andhra Pradesh and Tamil Nadu. While reporting many deserted stupas in the area around modern day Nepal and the persecution of Buddhists by Shashanka in the Kingdom of Gauda in modern-day West Bengal, Xuanzang complimented the patronage of emperor Harṣavardana (c. 590–647 CE). Xuanzang also noted that in various regions Buddhism was giving way to Jainism and Hinduism. After the fall of Harsha's empire, the Gangetic plain saw the rise of many small feuding kingdoms. This was to last until the rise of the Pāla Empire (8th–12th centuries) in the Bengal region. The Pālas were stanch supporters of Buddhism, and built several important Buddhist centers, such as Vikramashila, Somapura and Odantapuri. They also supported older centers like Nalanda and Bodh Gaya. It was at these great Buddhist centers that scholars developed the philosophies of Vajrayana, Abhidharma, Madhyamaka, Yogacara and Pramana, as well as the study of linguistics, medicine, astronomy, music, painting, and sculpture. Great Buddhist scholars such as Atisha and Santaraksita date from this period. Under the Pālas, Vajrayana Buddhism thus flourished and spread to Tibet, Bhutan and Sikkim. A milestone in the decline of Indian Buddhism in the North occurred in 1193 when Turkic Islamic raiders under Muhammad Khilji burnt Nālandā. By the end of the 12th century, following the Islamic conquest of the Buddhist strongholds in Bihar and Bengal by Delhi Sultanate's Muhammad bin Bakhtiyar Khalji, and the loss of political support coupled with social pressures, the practice of Buddhism retreated to the Himalayan foothills in the North and Sri Lanka in the south. Additionally, the influence of Buddhism also waned due to Hinduism's revival movements such as Advaita, and the rise of the bhakti movement. Vajrayāna Under the Gupta and Pala empires, a Tantric Buddhist movement arose, variously named Vajrayāna, Mantrayāna, Tantric Buddhism and