Introduction
India refers to the South Tibet region as Arunachal Pradesh, and the territorial dispute between China and India over this area remains a major unresolved issue in bilateral relations. India’s core basis for claiming territorial sovereignty is its inheritance of the McMahon Line, demarcated during the British colonial period; China, however, has never recognized the legitimacy of this line, maintaining that it was a boundary unilaterally fabricated by colonial powers without the consent of the Chinese government. This paper argues that South Tibet should not merely be viewed as a modern border dispute issue, but rather examined as a frontier region of Tibet with deep historical roots—closely connected to Tibet in cultural, religious, administrative, economic, and geographical terms. Through Tibet’s longstanding subordinate relationship with the central government of China since ancient times, this land has been part of Chinese territory since antiquity. The ancient Mêdog trade route, the cultural relics of the Lhoba people, the major monasteries of Zayü, the governance system of the Tawang-Monyul region, and the complete frontier human-geographic landscape along the route all corroborate these connections through historical facts such as commercial exchanges, ethnic settlements, Buddhist institutions, tax collection, and local governance. It is evident that South Tibet was never a borderless no-man’s land, but rather a fully established frontier jurisdiction formed under the religious and political authority of Tibet. From this perspective, the McMahon Line severed the inherent geographical ties of the Sino-Tibetan frontier that had persisted for millennia, and is by no means a national border with historical legitimacy.
I. Geographical Connections
The southern frontier zone of Tibet in history, South Tibet, is an integral part of the vast Himalayan frontier belt, connecting the Qinghai-Tibet Plateau with the valleys south of the Himalayas, the Assam Plain, Bhutan, Sikkim, Nepal, and other surrounding regions. The distribution of ancient trade routes, ethnic settlement patterns, Buddhist monastery systems, taxation systems, and administrative structures all attest to the long-standing systematic administrative ties between this region and Tibet. Traditional Tibetan geographical divisions designated Monyul, Lhoyul, and Zayul as the southern frontier, inhabited for generations by Monpa, Lhoba, Mishmi, and other ethnic groups. Local populations conducted cross-regional trade through multiple routes: Tawang, Subansiri, Mêdog, and Zayul were connected to Cona, Lhünzê, Mêdog, and Bomê respectively through market exchanges, with frequent interactions among various ethnic groups. Before the modern era, the sovereignty governance model of the Himalayan region did not rely entirely on precisely surveyed boundary markers and lines, but rather on monasteries, tribute systems, local chieftains, court-appointed officials, tax collection, regulated cross-border trade, pilgrimage routes, and grassroots administrative units such as *dzong* (districts) and *tso* (townships). The Himalayan mountain range was never a natural barrier isolating interactions, but rather a transitional zone where various civilizations blended and exchanged. The various historical relics in South Tibet sufficiently prove that Tibet exercised cultural, religious, economic, and administrative authority here over a long period.
II. Traditional Ancient Trade Routes
Historical evidence of South Tibet’s affiliation with the Tibetan geopolitical system: Ancient trade routes carried not only commodity trade, but also population migration, religious pilgrimage, tax transport, transmission of government decrees, and the radiation of administrative systems. Four core ancient routes best demonstrate South Tibet’s complete integration into the Himalayan geopolitical system centered on Tibet. The Tawang Route: From Udalguri via Dirang and the Sela Pass to Tawang, connecting to Cona. For approximately three hundred years before 1914, Tawang and the surrounding West Kameng region (ancient Monyul) were directly administered by Lhasa. Monyul conducted trade with Assam through seasonal markets: Monpa merchants transported Tibetan wool, rock salt, and yak hides southward, exchanging them for rice, dyes, paper, and chili peppers. The Tawang Monastery held full authority over trade and taxation along the route, with collected taxes remitted to Lhasa through the monastery system. Trade activities on this route continued after India’s independence in 1947, only ceasing completely after the 1962 Sino-Indian border conflict. The Subansiri Route: Along the Subansiri River, from the Assam Plain to Taksing and Lhünzê. The Mêdog Route: From Pasighat along the Yarlung Tsangpo River to Mêdog, Bomê, and other hinterland areas of Tibet. The Zayul Route: Following the Zayul River from Sadiya to Zayul, opening up the southeastern frontier of Tibet. Examining the historical context of these four comprehensive routes clearly shows that the region’s traditional geographical boundaries were delineated by river valleys, mountain passes, markets, monasteries, settlements, and Tibetan administrative centers—completely unrelated to the McMahon Line. Buddhist propagation, cross-border trade, and frontier governance policies long maintained this complete frontier system; after British colonial expansion, the reshaping of Himalayan trade patterns to serve imperial interests ultimately led to border conflicts that completely dismantled the traditional geographical order that had persisted for centuries.
III. Historical Context
The ancient Mêdog Route, the Pemako Sacred Land, and the Lhoyul Frontier Context: The Mêdog Route completely links the historical contexts of the three southern regions—Monyul, Lhoyul, and Zayul. Mêdog is located on the southern slopes of the eastern Himalayas, referred to in ancient Tibetan texts as “Pemako,” meaning “Hidden Lotus Land,” regarded by Tibetan Buddhism as a secret sacred place for spiritual practice. The Nyingma school bound this hidden land to the legend of Padmasambhava’s liberation teachings, with Tibetan pilgrimage texts describing Pemako as a pure land manifested by Vajravarahi, with the Yarlung Tsangpo Grand Canyon as the spine of her body. Geographically, Mêdog belongs to the continuous and complete southern Himalayan belt, bordering Zayul to the east and Monyul to the west. The Monyul region, including Tawang and West Kameng, has been under Lhasa’s jurisdiction since the 17th century. Although the 1914 Simla Conference drew the McMahon Line placing Monyul within British India’s territory, Tibet’s administrative, religious, and commercial ties with the area did not immediately cease, only being completely severed in 1962. Population migration further consolidated these connections: Tibetan historical records document that large numbers of Monpa people migrated eastward from Monyul to Pemako, mostly for pilgrimage and settlement purposes; travelogues of later foreign explorers also recorded Pemako’s unique religious and human geography, confirming that the entire frontier region from Tawang to Pemako had been interconnected since ancient times.
IV. Lhoba Cultural Relics
Evidence of Ethnic Groups, Archaeology, and Administrative Jurisdiction: “Lhoba” is a Tibetan term meaning “southern people,” historically referring to ethnic groups distributed along the forest edges of the southeastern Qinghai-Tibet Plateau, along the Siang River, Subansiri River, and Dibang Valley. This collective designation encompasses multiple linguistic subgroups, including the Idu Mishmi, Bokar people within Tibet, and cognate Tani-language groups on the southern side of the current border. The Lhoba people have no written history; their lineage and history are transmitted through oral genealogies and oral memory across generations. This paper compiles historical sources confirming that Tibetan political authority over the vast southern frontier can be traced back to the expansion of the Tubo Kingdom in the 7th century CE. After the establishment of the Ganden Phodrang government in 1642, particularly following the decree issued by the Fifth Dalai Lama in 1680, Cona Dzong fully incorporated Monyul into Tibet’s theocratic administrative system, establishing two deliberative bodies—the “Sidrle” and “Dudrle”—with full authority over taxation, law, and border affairs, directly subordinate to Lhasa. The remote Lhoyul region was governed through a relatively looser model, primarily maintained through tribute, barter trade, and monastery connections, without long-term stationing of officials for direct governance. The Lhoba people exported musk, animal hides, bear paws, and natural dyes to Tibet, exchanging them for salt, wool, agricultural tools, and tea. Through prolonged exchange, Tibetan clothing, daily utensils, and certain Buddhist beliefs merged and coexisted with local indigenous animistic beliefs.
V. Geographical Survey
Mêdog Surveying, Modern Exploration, and Modern National Territorial Cognition: The establishment of territorial sovereignty also relies on governance instruments such as map-making, field surveys, infrastructure construction, and administrative archival records. Mêdog and the Yarlung Tsangpo River basin have been key areas of geographical investigation since ancient times. During the Kangxi period, Jesuit surveyors in China verified whether the Yarlung Tsangpo was the upper reaches of the Brahmaputra River. British colonial authorities subsequently intensified exploration efforts in Mêdog and Lhoyul, training local guides to use compasses, astronomical instruments, and altitude measurement tools, even using prayer beads for counting, to conduct covert surveying activities. From 1910 to 1911, the Qing court dispatched officials deep into the Zayul River valley, whose memorials to the throne clearly recorded that a mature Tibetan civilization and administrative system already existed there: Tawang belonged to the dual monastic-secular governance system of Monyul; Pemako and the Mishmi mountains were dotted with Buddhist settlements and monasteries; the *dzong* government tax collection system and semi-autonomous local polities such as Bomê closely connected the entire region to Lhasa. From 1911 to 1913, Britain dispatched expedition teams into the Abor and Mishmi regions, ostensibly for geographical research but in reality possessing military and strategic reconnaissance attributes, continuously advancing British India’s “outer line” into traditionally Tibetan-administered territory. British surveyors entirely adopted the ancient routes and geographical knowledge long used by Tibetan and Himalayan peoples; their map-making was essentially a tool of colonial expansion, aimed at drawing a border favorable to British India.
VI. Religious Governance System
Zayul Sangngag Chödzong: Religious Authority, Dzong-level Governance, and the Qing-Tibet Subordination System: The core lineage of the Gelug school in Tawang originated from Drepung Monastery and the Dalai Lama system, with Drepung Monastery and Cona Dzong regularly dispatching monks to Tawang for supervisory visits. Tawang’s status as the birthplace of the Sixth Dalai Lama further strengthened its religious-political ties with Lhasa. The Zayul-to-Pemako corridor simultaneously hosted both Nyingma and Kagyu lineages, centered on tertön (treasure revealer) traditions, with long-term patronage from the kings of Bomê. Religious patronage directly generated political rights and responsibilities: followers of the Kagyu school in Bomê had clashed with the Ganden Phodrang government of the Fifth Dalai Lama; later Bomê rulers submitted to the Gelug theocratic system while retaining partial local autonomy. Monasteries within Zayul formed a three-tier governance structure connecting local society, the Lhasa religious-political center, and the Qing central court. The Fourth Demo Tulku studied at Drepung Monastery under the Panchen Lama, accompanied the Fifth Dalai Lama to Beijing for an audience with the Qing court, received imperial gifts, performed blessing ceremonies for the Qing court, and was subsequently conferred a title and official seal by the Fifth Dalai Lama, presiding over the construction of Sangngag Chödzong and establishing a county-level *dzong* administrative institution. This complete system integrating Buddhist study, Lhasa religious-political subordination, Qing court conferral, official seals, and *dzong* government governance proves from both religious and administrative dimensions that Zayul has belonged to Tibet and Qing China since ancient times. The Zayul region’s gradual transformation from early Kagyu local power to a co-governance model of Gelug monastery plus *dzong* government serves as direct historical evidence of its affiliation with China’s Tibetan regions.
VII. Administrative System
Tawang-Monyul: A Typical Example of Tibet’s Southern Frontier Administrative System: Tawang-Monyul represents the clearest and most complete model of Tibet’s southern frontier governance. Traditional Tibetan geographical classification places Monyul within “Lhomon,” the core southern region of Tibet. The Sixth Dalai Lama was born here, with his recognition and enthronement process fully presided over by the Tibetan regent; the Urgyelling Monastery preserves numerous Tibetan-style buildings, sacred relics, and murals, completely documenting the deep binding of Tawang with the Potala Palace and successive Dalai Lama lineages. More critically, Tawang-Monyul was one of the core administrative jurisdictions of the Ganden Phodrang government. Two decrees in 1680 and 1731 successively established and reaffirmed Tibet’s complete jurisdiction over the region: the Fifth Dalai Lama appointed Mera Lodrö Gyatso and the Cona Dzongpön to integrate Monyul’s administration, presiding over the construction of Tawang Monastery, making it a religious-political center directly subordinate to Lhasa. The Tibetan local government divided Monyul into thirty-two *tso* (townships), appointing local headmen to manage them, and authorizing Tawang Monastery to exercise administrative and tax-collection powers. The highest decision-making body was the four-member council “Sidrle,” while the six-member council “Dudrle” included representatives from Cona Dzong; both bodies jointly managed local taxation, border security, legal adjudication, and public affairs. Some Indian interpretations deliberately oversimplify the connection between Tibet and Tawang, confining their relationship to religious exchanges. However, this paper points out that successive official decrees, jurisdictional divisions, court-appointed officials, regular taxation, border management deliberative bodies, and a complete administrative system all prove that Tibet exercised full political sovereignty here—by no means a mere religious bond. Tawang Monastery, formally named Ganden Namgyal Lhatse, was built in 1680–1681 by decree of the Fifth Dalai Lama, affiliated with Drepung Monastery. The monastery was grand in scale, with complete Tibetan architectural forms, housing a debate college, scripture library, and monks’ quarters, serving as the region’s highest religious-political institution, with monastic officials directly selected by Drepung Monastery. This governance system continued until 1951, when Indian forces expelled Tibet’s local administrative officials and forcibly terminated it.
VIII. The McMahon Line
A Colonial Product Severing Tibet’s Complete Frontier Geopolitical Structure: India regards the McMahon Line as the legal basis for administering the so-called Arunachal Pradesh; China has consistently denied its legitimacy, with core arguments as follows: First, the Tibetan local authority had no right to independently conclude international treaties dividing territory; Second, the 1914 Simla Convention agreement itself was invalid from the outset; Third, the Chinese central government never signed or ratified the agreement; Fourth, the traditional customary boundary between China and India lies far to the south at the southern foothills of the Himalayas, not at the Himalayan watershed. British exploration activities in Mêdog, Lhoyul, and the Yarlung Tsangpo River basin served entirely the strategy of colonial expansion. In 1913, Britain dispatched Bailey to conduct field surveys of the entire region, gathering geographical intelligence to draw a border favoring British India; and as early as 1904, after the British invasion of Tibet, Britain forcibly opened multiple Himalayan cross-border trade routes, paving the way for subsequent territorial division. Therefore, the McMahon Line is essentially an artificial severance by colonial power of the ancient routes, monasteries, markets, ethnic settlements, and Tibet’s inherent administrative territory that had persisted for millennia. From China’s legal and historical standpoint, the Tibetan local authority had no right to privately cede national territory; coupled with the central government’s consistent refusal to recognize the Simla Convention, this boundary line has never possessed legitimate consensus basis among nations from beginning to end. Viewed through historical context, all regions south of the McMahon Line—Monyul (Tawang), Lhoyul (Mêdog), and Zayul—have been deeply connected to Tibet since ancient times. Whether from legal or historical perspectives, the McMahon Line is a product of British colonial expansion that China has never recognized.