The geopolitical implications of Xuanzang’s round-trip

The Chinese Buddhist monk Xuanzang’s journey to India and back is well-known (see Samanth Subramanian’s review of Mishi Saran’s book in Pragati). What is not so well-known is that his trip led, unintentionally, to a diplomatic spat between the China and India that ultimately resulted in the first Chinese military expedition to ‘punish’ the Indians.

Harsha-vardhana of India had earlier sent emissaries to Chang’an and in 643, around the time of Xuanzang’s departure from India, a Tang mission under a military official called Wang Xuance had repaid the compliment. Five years later, in 648, Wang Xuance was back in India at the head of a more impressive embassy that was doubtless influenced by Xuanzang’s reports on Harsha.

But this time ambassador Wang Xuanxe received a very different reception. Harsha had died the previous year, his empire was already crumbling, and a Brahminical reaction had set in against the Buddhist community. Evidently, Xuanzang’s long sojourn and his influence on Harsha had encouraged the idea that Chinese support was enabling Indian Buddhists to subvert the political primacy claimed by India’s priestly caste. Wang Xuance’s 648 mission was therefore waylaid. Its valuables were stolen, its personnel detained and Wang Xuance himself barely escaped with his life. He escaped to Tibet.

There he took advantage of a rare moment of amity in Sino-Tibetan relations. In the 630s the great Srong-brtsan-sgam-po [Songtsen Gampo] had been engaged in sporadic warfare with Tang forces in both Sichuan and Qinghai. Unusually the Tibetans fought not to keep the Chinese out of Tibet but to secure closer relations with them, or rather, to secure parity of treatment with that extended by Chang’an to their local rivals…(In 641) with a view to ending their raids, Tang Taizong had granted the Tibetans what was in effect a ‘peace-through-kinship’ treaty. It was sealed as usual with the dispatch of an imperial princess. Further exchanges followed, the Tibetans regarding them as evidence of Tang vassalage and the Tang as evidence of Tibetan vassalage.

Into this happy state of mutual misunderstanding straggled Wang Xuance on his way back from his rebuff in India. The rout of an embassy from the Son of Heaven, not to mention the Heavenly Qaghan, could not go unavenged. Wang Xuance demanded troops for a retaliatory attack on India and the Tibetans obliged. It was thus a joint Sino-Tibetan force that in 649, probably by way of the Chumbi pass between Sikkim and Nepal, crossed the Great Himalaya and inflicted heavy defeat on Harsha’s successors. ‘Thereupon’, says the standard Tang history, ‘India was overawed.’

Elsewhere it is recorded that Wang Xuance brought back as prisoner to Chang’an the man who had supposedly usurped Harsha’s throne. A statue of ‘this contumacious Indian’ was erected among the many in front of Tang Taizong’s tomb and ‘so [the Indian] found lasting fame—but as a trophy and an emblem’. Needless to say, Indian tradition is blissfully ignorant of all this. The Sino-Tibetan incursion probably affected only a corner of Bengal and had no known repercussions. Though a Chinese assault on Indian territory had been shown to be feasible, it would not be repeated until the 1960s. [John Keay/China – A History pp243-244]