Mangsong Mangtsen (Tibetan: མང་སྲོང་མང་བཙན་, Wylie: mang srong mang btsan) was the third btsanpo (emperor) of the Tibetan Empire, reigning from approximately 650 to 676 CE. He was the grandson of the renowned Songtsen Gampo, the unifier of Tibet, and his reign marked a period of continued expansion and consolidation of Tibetan power, particularly against Tang China and the Tuyuhun.
Early Life and Accession
Mangsong Mangtsen was the son of Gungsong Gungtsen (Songtsen Gampo's son) and 'A-zha Mongs-za Khrig-mo-lod. His father, Gungsong Gungtsen, is believed to have died young, potentially even before his own father, Songtsen Gampo. Consequently, when Songtsen Gampo died around 649 or 650 CE, the young Mangsong Mangtsen, still a child, ascended the throne.
Regency of Gar Tongtsen
Due to Mangsong Mangtsen's minority, the actual power during the early part of his reign was held by the highly influential and capable chief minister, Gar Tongtsen Yulsung (mgar stong btsan yul zung). Gar Tongtsen had previously served Songtsen Gampo and was instrumental in shaping the early Tibetan Empire. Under his guidance, Tibet continued its assertive foreign policy.
Military Expansion and Foreign Relations
The period of Mangsong Mangtsen's reign, dominated by Gar Tongtsen's leadership, saw significant military successes for the Tibetan Empire:
- Conquest of Tuyuhun: In 663 CE, Tibet decisively conquered the Tuyuhun kingdom, a powerful nomadic confederation to the northeast of Tibet. This victory eliminated a significant rival and secured Tibet's northern and eastern frontiers, giving them direct access to the Silk Road.
- Conflicts with Tang China: The annexation of Tuyuhun led to increased friction with Tang China, who viewed the Tuyuhun as their vassal. This sparked a series of major engagements between Tibet and Tang. In 670 CE, Gar Tongtsen led the Tibetan army to a crushing victory over the Tang forces at the Battle of Dafeichuan (大非川), inflicting a heavy defeat on the renowned Tang general Xue Rengui. This battle solidified Tibetan control over much of the Tarim Basin and the crucial trade routes.
- Expansion into Central Asia: Tibetan influence expanded further into Central Asia, challenging Tang dominance in the region.
Internal Affairs
While the focus of historical records from this period is largely on military campaigns, it can be inferred that the internal administration of the Tibetan Empire continued to develop and strengthen under the stability provided by Gar Tongtsen. The capital remained at Lhasa, and the organizational structures established by Songtsen Gampo were likely consolidated. Gar Tongtsen died in 667 CE, after which his sons continued to hold significant power in the government, maintaining the strong ministerial lineage.
Death and Succession
Mangsong Mangtsen died in 676 CE. He was succeeded by his son, Düsong Mangpojé (Tridé Gungtsen), who continued the expansionist policies of his predecessors.
Legacy
Mangsong Mangtsen's reign is crucial for understanding the consolidation and expansion of the Tibetan Empire. Although much of the glory for the military and political achievements of this era goes to his regent Gar Tongtsen, Mangsong Mangtsen's long reign provided the necessary continuity for the empire to mature from its nascent stages under Songtsen Gampo into a formidable power in Central Asia, directly challenging the might of the Tang dynasty.