Tridu Songtsen () (668 – 704), also known as Dusong Mangban, was the 36th King (Tsenpo) of Tibet from 676 until his death in 704.

Ascent to throne Dusong ascended the Tibetan throne after the death of his father, Mangsong Mangtsen, in 676. The Old Book of Tang says that Dusong was eight years old in 679—nine years old by Western reckoning.Lee (1981), pp. 20–21. He was, therefore, presumably born in 670 and was six or seven years old when he began his reign. Due to his youth, he was enthroned with the minister Gar Tongtsen's second son, Khri 'bring, to act as regent.Ancient Tibet: Research materials from the Yeshe De Project, p. 233. 1986. Dharma Publishing, California. .

Political and military activities In 676 the Tibetans made raids on Shanzhou, Guozhou, Hezhou (now Linxia), Diezhou, Migong and Danling in Gansu. The Chinese counterattacked, defeating the Tibetans at Longzhi. The Chinese army led by Li Jingxuan were soundly defeated near Qinghai Lake,Shakabpa, Tsepon W. D. Tibet: A Political History, p. 31. (1967), Yale University Press, New Haven and London. however, and by the end of 677 Tibet controlled the whole of the Tarim Basin and the mountainous regions to the southwest.Beckwith, Christopher I. The Tibetan Empire in Central Asia. A History of the Struggle for Great Power among Tibetans, Turks, Arabs, and Chinese during the Early Middle Ages, 1987, Princeton: Princeton University Press. , p. 43.

Revolt of Zhangzhung and the leadership of his mother, Khrimalod, and his ministers The western kingdom of Zhangzhung revolted soon after the death of King Mangsong Mangtsen (also known as Trimang Löntsen, ) (r. 650–677), the son of Songtsen Gampo, but was brought back under Tibetan control by the "firm governance of the great leaders of the Gar clan" the following year.Shakabpa, Tsepon W. D. Tibet: A Political History (1967), p. 32. Yale University Press, New Haven and London.

Under the leadership of his powerful mother, Khri ma lod, and his ministers and generals during the early part of his reign, Tibet continued to maintain and even expand its territory.

The Tibetans gained control of an important Tang fortress at Anrong in 678Lee (1981), p. 19. on the Min River north of Chengdu which they held for more than sixty years as a frontier post. According to an 11th-century Chinese history, the Erhe people from the Erhai Lake region in 'Jang, one of the princedoms around the upper waters of the Yangtze which later made up Nanzhao,Richardson, Hugh. "Bal-po and Lho-bal." Bulletin of the School of Oriental and African Studies, No. 46 (1983), p. 136. submitted to Tibet this same year, asking for an alliance against the Chinese. The Old Book of Tang reports:

The Chinese army led by Wei Daijia unsuccessfully invaded Tibet in 689. Many of the soldiers died and the commander of the troops was executed for his failure.Lee (1981), p. 22. It was also in this year that the Tibetan princess Khri-bangs was married to an Azha chief to strengthen bonds between the two peoples. They had a son named Ma-ga Thogon Khagan.

Two Tibetan generals defected to the Chinese with their troops in 692. The Chinese then defeated the Tibetans, regaining control of the Tarim BasinLee (1981), pp. 22–23. and the lucrative trade routes to the West, which they held for almost a century before the Tibetans reconquered the region.Ancient Tibet: Research materials from the Yeshe De Project, p. 234. 1986. Dharma Publishing, California. .

The Turkish Khagan Ton-ya-bgo (Ch. Ashina Tuizi), chief of the Western Dulu in Dzungaria, visited the Tibetan court in 694.Ancient Tibet: Research materials from the Yeshe De Project, p. 235. 1986. Dharma Publishing, California. . together they attacked and defeated the Chinese at Lengjuan.

The following year Dusong successfully attacked Lintao, and Liangzhou.Pelliot, Paul. Histoire Ancienne du Tibet, p. 92. Paris. Libraire d'amérique et d'orient. 1961.

Gar Trinring Tsendro went to Chang'an in 696 to try to negotiate peace with Empress Wu Zetian (r. 684–705) on condition that China remove all troops from Central Asia and divide the Western Turks between China and Tibet. She refused to negotiate.

Dusong realised that members of the Gar family had become independent warlords and posed a threat to the central authority of the king. So, in 699 he pretended to organise a great hunt and then had his men turn on members of the Gar and their supporters. Then he personally marched north and confronted Gar Trinring Tsendro, who surrendered without a fight and, according to the Old Book of Tang, committed suicide. His brother fled to China.Lee (1981), p. 11.

After this, Dusong asserted the right of the power of the king over his ministers.

Dusong personally led 10,000 troops into four battles in some unnamed place to the northeast in 702. The next year he "established his authority over the 'Jang (Nanzhao), he imposed tribute on the White Mywa, he subdued the Black Mywa (probably the Miao people),Beckwith, C. I. "The Revolt of 755 in Tibet", p. 5 note 10. In: Weiner Studien zur Tibetologie und Buddhismuskunde. Nos. 10–11. [Ernst Steinkellner and Helmut Tauscher, eds. Proceedings of the Csoma de Kőrös Symposium Held at Velm-Vienna, Austria, 13–19 September 1981. Vols. 1–2.] Vienna, 1983. and so on."Bacot, J., et al. Documents de Touen-houang relatifs à l'Histoire du Tibet. (1940), pp. 149–50. Libraire orientaliste Paul Geunther, Paris. (Translated from the French)

Relations with Nepal It seems Nepal remained tributary to Tibet throughout the reign of Dusong. A Nepalese stone edict of 695, during the reign of the Licchavi king, Shivadeva II, records: "because of the reason that Nepal paid taxes to Tibet, five officials must take the responsibility of the coolies who carry the luggage every year."Tenzin, Acharya Kirti Tulku Lobsang. "Early Relations between Tibbet and Nepal (7th to 8th Centuries)." Translated by K. Dhondup. The Tibet Journal, Vol. VII, Nos. 1 &2. Spring/Summer 1982, p. 85. This is confirmed by the Old Book of Tang which record that in 703, soon after Dusong's death, "the subject countries in the south, such as Nepal and others, all revolted."Lee (1981), p. 28. Furthermore, the Tibetan Annals record that Dusong spent the summers of 690, 697 and 699 in Nepal.Bacot, J., et al. Documents de Touen-houang relatifs à l'Histoire du Tibet. (1940), pp. 37-39.

His wives and son Dusong he married two women from important Tibetan clans—'Damgyi Chokroza', and Chimza Tsenmotok (Wylie: mChims-bza' bTsan-ma thog), Princess of Chim, with whom he had a son Tride Tsuktsen (also known later as Me-Agtsom) in 704.Ancient Tibet: Research materials from the Yeshe De Project, pp. 238, 242. 1986. Dharma Publishing, California. . It seems Dusong also had a Turkish bride, as the Tibetan Annals record the death of the princess "Gatun" (= Turk: Khatun?) in 708.Bacot, J., et al. Documents de Touen-houang relatifs à l'Histoire du Tibet. (1940), p. 42. Libraire orientaliste Paul Geunther, Paris. (Translated from the French)

His support of Buddhism Although Dusong is primarily remembered as a warrior, according to the Testament of Ba, he supported Buddhism and had a temple called Khri rtse built in Gling Khams, "and so on",dBa' bzhed: The Royal Narrative Concerning the Bringing of the Buddha's Doctrine to Tibet, p. 33. Translation and Facsimile Edition of the Tibetan Text by Pasang Wangdu and Hildegard Diemberger. Verlag der Österreichischen Akadamie der Wissenschafen, Wien 2000. . which is recorded on an inscription at sKarchung written by Emperor Sadnalegs about a century later.Richardson (1985), p. 75.Beckwith, C. I. "The Revolt of 755 in Tibet", p. 3 note 7. In: Weiner Studien zur Tibetologie und Buddhismuskunde. Nos. 10–11. [Ernst Steinkellner and Helmut Tauscher, eds. Proceedings of the Csoma de Kőrös Symposium Held at Velm-Vienna, Austria, 13–19 September 1981. Vols. 1–2.] Vienna, 1983.Richardson (1985), pp. 73, 75.

Dusong's death and succession Dusong died in 704 in battle in Mywa territory in modern Yunnan. The Tang Annals state he was on his way to suppress tributary kingdoms on the southern borders of Tibet, including Nepal and parts of India. There was a dispute among his sons but, "after a long time" the people put seven year old Qilisuzan (), later known as Me Agtsom, on the throne.Pelliot, Paul. Histoire Ancienne du Tibet. Paris. Libraire d'amérique et d'orient. 1961, p. 12.Lee (1981), p. 13.

Dusong is buried next to his father in the Royal Burial grounds near Yarlung.Ancient Tibet: Research materials from the Yeshe De Project, p. 239. 1986. Dharma Publishing, California. .

Notes

References Richardson, Hugh E. (1985). A corpus of early Tibetan inscriptions. London: Royal Asiatic Society. Lee, Don Y. (1981). The History of Early Relations between China and Tibet: From Chiu t'ang-shu, a documentary survey. Bloomington, IN: Eastern Press.