In June 1900 a small walled-up chamber — Cave 17 of the Mogao cave-temple complex at Dunhuang, the so-called Library Cave — was found to contain tens of thousands of manuscripts, paintings, and ritual objects accumulated between the fifth and early eleventh centuries. Why the chamber was sealed, and in exactly which year, has been debated since its discovery without resolution: the leading hypotheses (disposal of sacred waste, concealment from the Kara-Khanid or Western Xia military threat, considered closure of storage no longer in use, and a protective scripture deposit in anticipation of the Buddhist Final Dharma believed to begin in 1052) all rest on circumstantial evidence, and the most recent systematic treatment of the cave's contents (2024) states that the reason and date of the sealing remain conjecture. The problem is to establish the sealing's motive and precise date on direct documentary, epigraphic, or archaeological evidence, thereby adjudicating among the competing explanations.

Background

The Mogao Caves are a Buddhist rock-cut cave-temple complex near the oasis town of Dunhuang, at the northwestern end of the Gansu corridor in China, in active use and under continual repainting from the fourth century onward. In June 1900 the self-appointed caretaker of the site broke through a plastered wall on the northern side of the corridor of Cave 16 and revealed a small hidden chamber, now numbered Cave 17 and known as the Library Cave. It held tens of thousands of manuscripts and printed documents in Literary Sinitic, Tibetan, Khotanese, Sogdian, Old Uyghur, and Sanskrit, together with silk paintings, banners, textiles, and ritual objects — a closed assemblage that became the founding corpus of the modern field of Dunhuang studies. The chamber itself was originally the memorial chapel of the ninth-century monk Hong Bian, whose painted statue stood inside it; its earlier funerary and commemorative function is an active topic of research (Doumy and van Schaik 2024).

The historical window of the sealing is fixed only within broad limits. After the fall of the Tibetan empire, Dunhuang was ruled from 848 by the local Cao family under the name Guiyijun (the 'Return to Allegiance Army' regime), which maintained marriage and diplomatic ties with the neighboring Shazhou Uyghurs and the Buddhist kingdom of Khotan. The latest internally dated document from the cave, the donor's record F.32A, bears the date 1002. In 1006 the Islamic Kara-Khanid dynasty destroyed Buddhist Khotan; the Tangut Western Xia (Xi Xia) state conquered Dunhuang in the mid-1030s. The sealing must therefore fall between 1002 and the Western Xia conquest, and every finer determination depends on inference. No inscription, colophon, or archival record stating who sealed the cave, when, or why has ever been identified.

One line of explanation draws on East Asian Buddhist eschatology. The 'Final Dharma' or 'Age of Decline' (mofa) doctrine holds that after the Buddha's death his teaching passes successively through an Age of True Dharma, an Age of Semblance Dharma, and a final degenerate age in which the teaching survives only in material form; Chinese chronologies that counted 500 years of True Dharma and 1,000 years of Semblance Dharma placed the onset of the Final Dharma in the year 1052. Epigraphy of the Khitan Liao dynasty — notably the inscriptions of the Chaoyang North Pagoda of 1043–1044, which state that 'in a further eight years the Age of Semblance shall enter the Age of Decline' — shows that this expectation prompted concrete practices of burying and depositing scriptures as dharma relics. Sha Wutian (2020) argues that the Thousand-Buddha 'transformation tableaux' (murals depicting the Buddha preaching in transformed worlds) on the outermost repainting layer of Cave 16, the layer that conceals Cave 17's entrance, express exactly this Final Dharma thought, and that the expectation reached Dunhuang through Guiyijun–Liao diplomatic exchanges concentrated in 1006–1020.

The explanatory debate is a century old. The earliest proposals took the cave to be a repository of sacred waste, or a storage room sealed at the Xi Xia invasion and dated to 1035 (Pelliot 1908; the early views are documented and criticized in Rong 1999 and Terzi and Whitfield 2024). Rong Xinjiang (1999, restated in his 2013 book) argued that the cave was the book storehouse of the Three Realms Monastery and that the sealing followed soon after 1002, most plausibly prompted by news of the Kara-Khanid destruction of Khotan — while explicitly conceding the suggestion 'must remain tentative in the absence of more direct proof' and allowing eschatological belief as an alternative motive. A further view treats the sealing as a considered act once the storage space was full and no longer of use (van Schaik and Galambos 2011, as characterized in Terzi and Whitfield 2024). Sha Wutian (2020) renewed the eschatological line, placing the sealing circa 1006–1020 or slightly later. No hypothesis has been adjudicated: all agree that the evidence is circumstantial, resting on the material assemblage, the mural program covering the entrance, and the diplomatic and doctrinal milieu — and that dating the sealing runs through dating the cover-layer murals of Cave 16, for which no stratigraphic, pigment, or inscriptional dating exists, only stylistic comparison with other late Guiyijun caves.

Problem Statement

Determine why and exactly when the Dunhuang Library Cave (Mogao Cave 17) was sealed. Establish, on direct documentary, epigraphic, or archaeological evidence that is not already part of the published circumstantial record — a newly identified in-cave colophon or datable manuscript bearing on the deposit, a sealing inscription, or a controlled (stratigraphic, pigment, or absolute, not stylistic) dating of the mural layer that covers the cave's entrance — (i) the precise year, or narrowest defensible interval, of the sealing, and (ii) the motive, or combination of motives, of those who sealed it, thereby adjudicating among the competing explanations that remain live in the literature: disposal of sacred waste, concealment from the Kara-Khanid threat (after the fall of Khotan in 1006) or the Western Xia advance (mid-1030s), considered closure of storage no longer in use, and protective scripture-deposit in anticipation of the Final Dharma believed to begin in 1052. The published circumstantial record does not by itself settle the motive or the date of the sealing.

References

  1. Sha Wutian, 'A reexamination of the reasons for the closure of the Dunhuang Library Cave', Chinese Studies in History 53(3): 208–226 (2020). DOI 10.1080/00094633.2020.1783161, https://doi.org/10.1080/00094633.2020.1783161
  2. Rong Xinjiang (translated by Valerie Hansen), 'The Nature of the Dunhuang Library Cave and the Reasons for its Sealing', Cahiers d'Extrême-Asie 11: 247–275 (1999). DOI 10.3406/asie.1999.1155, https://doi.org/10.3406/asie.1999.1155
  3. Rong Xinjiang, translated by Imre Galambos, 'Lecture 4: The Nature of the Dunhuang Library Cave and the Reasons for Its Sealing', in Eighteen Lectures on Dunhuang, Leiden: Brill (2013), pp. 109–136. DOI 10.1163/9789004252332_006, https://doi.org/10.1163/9789004252332_006
  4. Paschalia Terzi and Susan Whitfield, 'Reconstructing a Medieval Library? The Contents of the Manuscript Bundles in the Dunhuang Library Cave', Silk Roads Archaeology and Heritage 1(1): 56–76 (2024). DOI 10.5334/srah.8, https://doi.org/10.5334/srah.8
  5. Sam van Schaik and Imre Galambos, Manuscripts and Travellers: The Sino-Tibetan Documents of a Tenth-Century Buddhist Pilgrim, Berlin: De Gruyter (2011). DOI 10.1515/9783110225655, https://doi.org/10.1515/9783110225655
  6. Paul Pelliot, 'Une bibliothèque médiévale retrouvée au Kan-sou', Bulletin de l'École française d'Extrême-Orient 8: 501–529 (1908). DOI 10.3406/befeo.1908.4297, https://doi.org/10.3406/befeo.1908.4297
  7. Mélodie Doumy and Sam van Schaik, 'The Funerary Context of Mogao Cave 17', in Buddhism in Central Asia III, Leiden: Brill (2024), pp. 373–400. DOI 10.1163/9789004687288_013, https://doi.org/10.1163/9789004687288_013
  8. Mélodie Doumy, 'Wang Yuanlu, the first "curator" of the Stein collection's Dunhuang corpus', Journal of the Royal Asiatic Society 35(4): 821–845 (2025). DOI 10.1017/S1356186325000161, https://doi.org/10.1017/S1356186325000161