By Neville Agnew

Just one hundred years ago, at the ancient Buddhist cave temples of Mogao in the remote desert of northwest China, a Daoist monk named Wang Yuanlu made an astonishing discovery.

Abbot Wang, as he is often called, had taken up residence as the self-appointed guardian of Mogao—the Caves of the Thousand Buddhas—close to the oasis town of Dunhuang, which centuries before had been the gateway from China to the western regions along the Silk Road. Until Wang took over the site, it seems to have been largely abandoned since the early Ming dynasty (1368-1644), a time when China had drawn in upon itself as the self-sufficient "Middle Kingdom." During the centuries of abandonment, Mogao, while undoubtedly used as a local religious center, was essentially forgotten. Windblown sands smothered the grottoes, and decay overtook the wooden temple facades built on the cliff face into which the caves were cut.

What Abbot Wang found by chance was a hidden library in Cave 17, sealed at the beginning of the 11th century. In it were tens of thousands of documents written in Sanskrit, Tibetan, Tangut, and other languages besides Chinese; silk banners; scrolls; and, most significantly, the Diamond Sutra, a Buddhist devotional text and the earliest known printed book, dated from the colophon to 868. There were also calendars, regional records, contracts for sale of land, and, famously, a model letter of apology to one's host for having imbibed too freely. In short, an extraordinary record of the early medieval Chinese world.

The abbot knew nothing of this detail, nor was his main concern the documents, though he recognized them as a trove of great value. His passion was for the cave temples, or grottoes, that honeycombed the face of the mile-long cliff—some five hundred of them extant, constructed over a period of a thousand years, from the 4th century to the 14th century. The fabulous paintings that covered every inch of the walls and ceilings and the exquisitely modeled and polychrome clay sculpture within the temples—these were the subject of his veneration.

The Peerless Caves

The ruins of the earthen fort and military granary at Yumenguan—known as the Jade Gate—some 90 kilometers to the west of Dunhuang, site of the Mogao grottoes. Photo: Francesca Piqué.

While Abbot Wang's interest in the grottoes was solely religious, the world has come to see the significance of Mogao as extending beyond the spiritual. Its designation as a World Heritage site in 1987 recognized how remarkably the wealth of heritage at Mogao captures the pageant of Chinese life and customs spanning a millennium.

There are many fascinating stories to tell about Dunhuang and Mogao, "The Peerless Caves." One is the story of Buddhism's spread into China and eventually into Korea and Japan. It was through this tiny oasis portal at the confluence of the two arms of the Silk Road, which skirt the fearful Takla Makan Desert on the north and south, that Buddhism was introduced from India in the first century. Another story is the plunder of the archive of Cave 17, the removal of many of its contents to museums around the world, and how this dispersal led to a flourishing international discipline of Dunhuang studies. Third, there is the study of a thousand years of Chinese Buddhism from the Mogao wall paintings and wall inscriptions, which reveal life in China at all levels of society. The cave art richly documents the costume, dance, and music of eight dynasties of Chinese history, as well as agriculture and daily existence in a remote outpost of the empire. Here are portraits of the nobles who commissioned the caves, along with their wives and retinues, named in inscriptions on the walls.

Wang Yuanlu, the Daoist monk who, a hundred years ago, discovered tens of thousands of ancient documents that had been sealed in Cave 17 of the Mogao grottoes at the beginning of the 11th century. Photo: Sir Aurel Stein. Courtesy the Oriental and India Office, The British Library.

A pile of some of the ancient manuscripts discovered at the turn of the century in Cave 17 of the Mogao grottoes. Photo: Sir Aurel Stein.Courtesy the Oriental and India Office, The British Library.

Then there is the two-thousand-year history of Mogao and Dunhuang. Dunhuang was founded in 111 B.C.E. as a commandery, the last outpost of newly unified Han China. As elsewhere in China, Dunhuang's history is one of conquest by fierce neighbors—in this case, the Northern Wei and the Tibetans—and reconquest by the ethnic Chinese. The history of the north of China is one of turmoil and flux, as nomads and migrants from the mountains and steppe swept down upon the agriculturalists. This conflict led to the construction of the first Great Wall, started by the unifier of China, Qin Shi Huangdi, the first emperor of the Qin dynasty (221-206 B.C.E.), a task that continued intermittently over the centuries and was greatly extended during the Ming dynasty. Remnants of the wall and watchtowers, built of earth during the Han dynasty (206 B.C.E.-220 C.E.), can still be seen west of Dunhuang at Yumenguan, the so-called Jade Gate through which passed annual tributes of precious jade from present-day Xinjiang. Here in the desert lie neatly stacked piles of reeds, ready as they have been for 20 centuries to be lit as signal fires on the approach of the enemy.

From the middle of the 20th century, there is the story of the 1943 establishment of the Dunhuang Academy as the organization responsible for Mogao, as well as its trials and vicissitudes through the Cultural Revolution until today. Under remarkable directors and able staff, it has developed into an intellectual and cultural establishment of the first rank. For the last decade, the Getty Conservation Institute has collaborated with this unique institution, working with the academy to preserve the art of Mogao through research, training, and conservation.

The Mogao grottoes, once a site almost unknown to all but a few specialists, is now a mecca for scholars and tourists from around the world.

Dunhuang Scholarship

Though Marco Polo would have passed through Dunhuang, the first recorded European visit of Mogao in modern times was in 1879 by the geographer and explorer Lajos Lóczy, a member of a Hungarian expedition. He subsequently mentioned it to a friend, Aurel Stein, a Hungarian-born British subject who was later knighted for his Central Asia explorations and for the archaeological collections (now in Britain and India) that he amassed. Having heard of the hidden library, Stein arrived at Mogao in 1907. Abbot Wang was no match against the determined blandishments of Stein, who removed thousands of scrolls on his first forays. In 1913 he returned, and obtained further hundreds of items. In his classic account of exploration in Central Asia, Stein wrote that when he first entered Cave 17, "the sight of the small room disclosed was one to make my eyes open wide. Heaped up in layers, but without perfect order, there appeared in the dim light of the priest's little lamp a solid mass of manuscript bundles rising to a height of nearly ten feet, and filling, as subsequent measurement showed, close on 500 cubic feet. The area left clear within the room was just sufficient for two people to stand in."

Stein was followed rapidly by others from France, Germany, Russia, and Japan. The American Langdon Warner, the last of the raiders, arrived on the scene in the 1920s, by which time authorities had given orders for the removal of the remaining manuscripts to Beijing. By this time, too, nationalism and even hostility to foreign archaeologists had grown strong in China, and the government, though weak, forbade removal of artifacts from sites in China. Nonetheless, Warner did get to Mogao and Dunhuang, and Dunhuang Academy staff today may show visitors a small area of wall painting in one of the caves which they say was in the process of being lifted by Warner when he was stopped from doing so.

A view of a portion of the facade of the Mogao grottoes. In the background is the nine-story pagoda enclosing Cave 96. Photo: Leslie Rainer.

A consequence of the diaspora of the Cave 17 library holdings is the rise of a vibrant field of international scholarship. For example, the International Dunhuang Project at the British Library actively publishes material on the Stein collection. The St. Petersburg branch of the Institute of Oriental Studies at the Russian Academy of Sciences is organizing a conference, "Preservation of Dunhuang and Central Asian Collections," in St. Petersburg in September of this year. Next year the Dunhuang Academy will celebrate the discovery of the Cave 17 library with an international conference at the site. Wang's mud-brick temple in front of the grottoes, where he was suborned by Stein into parting with the treasures of the library, is being reconstructed for the event by the Dunhuang Academy, even though there is ambivalence about the monk himself. On the one hand, he is the discoverer; on the other hand, he sold out—and for a pittance at that.

Today China bitterly resents the loss of the Cave 17 library, mainly to Western institutions. To a significant degree, Chinese scholars have been hampered by lack of access to the material, and consequently, a great deal of research on the documents has been done elsewhere. Still, the wall paintings and sculpture at Mogao remain remarkably well preserved, due in part to the extremely dry climate and the remoteness from arenas of warfare. Most damage has been the result of human activity—primarily, it seems, in the first half of the 20th century. The opening of the region to modern road traffic and the lack of site staff and protection before 1943 meant that casual visitors could (and did) deface paintings and mutilate or loot clay sculpture. Also, around 1920, Russian émigrés fleeing the aftermath of the revolution spent a winter in some of the grottoes, and soot from their cooking and heating fires completely blackened paintings.

In 1980, Mogao was opened to tourism, which grew from a trickle to a torrent by the late 1990s. The expansion of Dunhuang airport allows jets to fly daily from Beijing, Xian, and Lanzhou through most of the year. Only in winter, due to the intense cold, is tourism slow. Tourism has transformed Dunhuang from a dusty provincial town of a few thousand inhabitants in the 1940s and 1950s, to a bustling city of street markets and new hotels funded by capital from Hong Kong and elsewhere. This influx has caused the Dunhuang Academy concern about the impact of too many visitors on the art. Mogao remains one of the best-managed sites in China, and the academy is striving to keep abreast of developments in conservation, site presentation, and management through collaborations with the GCI and other organizations, such as the Tokyo National Research Institute for Cultural Properties. To address one of these issues, the academy erected an exhibition hall on site with 10 full-scale, hand-painted copies of the most popular caves. Since the caves are not artificially lit and visitors must examine the wall paintings by flashlight, the copies are an alternative or complement to the experience of visiting the caves.

There is a long-standing tradition of copying the wall paintings, and the replication section is one of several large departments of the Dunhuang Academy (others include conservation, archives, visitor management, and art-historical research). Recently retired academy director Duan Wenjie, who came to Mogao as an art student in the late 1940s, has written, "I was in charge of the Mogao grottoes for nearly half a century and dedicated my life to copying work. I am deeply convinced that this work is a science unto itself. Copies painted by me and by artists devoting themselves to Dunhuang art have been exhibited at Lanzhou, Xian, Beijing, Shanghai, Tianjin, Shenyang, Hefei, and Taiwan, as well as India, Myanmar, Poland, Czechoslovakia, France, and Japan. . . . In the course of my copying work in the remote desert, I probed into the aesthetics and history of Dunhuang art. Thus, my theoretical research was built on a solid foundation. Dunhuang art will definitively play a positive role in the development of Chinese art and culture and that of the world as well."

The GCI at Mogao

The documentation team at work in Cave 85, recording the condition of the wall paintings. Photo: Leslie Rainer.

This year marks the 10th anniversary of the Getty Conservation Institute's work at Dunhuang. At the beginning of 1989, an agreement was made between the Getty Trust and the State Bureau of Cultural Relics (now the State Administration for Cultural Heritage, known as SACH). The agreement was deferred for one year after the events at Tiananmen Square in 1989, but planning continued. The first five years of GCI work focused on site stabilization, research on the environmental causes of deterioration, monitoring, and training. This phase culminated in an international conference at Mogao in October 1993, "Conservation of Ancient Sites along the Silk Road," which also commemorated the 50th anniversary of the Dunhuang Academy. Its purpose was to bring together site managers from the East and the West to exchange experience and knowledge (see Conservation, vol. 9, no. 1). Subsequently, the GCI and SACH formally evaluated the work done using independent experts from the United States and Europe, together with a team from China. Overall, their report was very positive; encouraged by this, the GCI has followed up with further collaboration.

The current work focuses on understanding in detail the problems of the deterioration of the wall paintings, the introduction of new materials and methods for the conservation of wall paintings, and research and training. Cave 85, a large Tang dynasty cave on ground level, has been chosen as the exemplar. The work plan follows the methodology of the developing China Principles, a collaboration of the GCI with SACH and the Australian Heritage Commission (see Conservation, vol. 13, no. 1). During the June 1999 campaign at Mogao, the two projects converged at the site. The draft China Principles for conservation and management of sites were further refined during this work in the context of conservation and site management at the macrolevel of Mogao. At the same time, the wall paintings team completed the condition recording and assessment following the same methodology, but at the microlevel at Cave 85.

(top) A portion of the wall paintings in Cave 85, depicting a variety of scenes from everyday life during the late Tang dynasty. Photo: Francesca Piqué. (bottom) A painting of Zhai Farong of the Dunhuang region, the principal donor for Cave 85. The portrait is located at the entrance to the cave. Photo: Sun Hong Cai.

A detail of the Tang dynasty paintings in Cave 85, depicting musicians with their instruments. These musical instruments have been recreated for performances at the Dunhuang Academy today.Photo: Neville Agnew.

The academy has assembled a large team to work in an integrated fashion with GCI staff, consultants, and partners. From the GCI side, the wall paintings group, led by Francesca Piqué, is completing the condition recording, while Shin Maekawa, who heads the environmental group, is studying the effects of moisture and humidity on the floor and bedrock of the cave. Michael Schilling's analytical team is studying binding media in the wall paintings, identifying pigments, and analyzing clays and the composition of the substrate and their response to humidity changes. As previously, between the two GCI campaigns per annum, in the spring and the fall, the Chinese staff at Mogao continues with data collection and processing.

To expand the training opportunities inherent in the project, the Dunhuang Academy has invited site managers from other sites along the Silk Road to participate in the collaboration. Currently, staff from the Xinjiang sites of Kizil and Jiaohe and from Lanzhou are team members. The team is further strengthened by Zheng Jun, a Courtauld-trained wall paintings conservator who is on staff at the Chinese National Institute for the Conservation of Cultural Property (CNIP) in Beijing. He, with two Dunhuang Academy staff members (Wang Xudong and Su Bomin), spent one month at the GCI in July 1999 for advanced training in analysis and digital documentation. Further training at the GCI is planned for academy environmental team members next year.

During the years of collaboration between the GCI and the Dunhuang Academy, productive professional and personal relationships have developed. The current director, archaeologist Fan Jinshi, has been at Mogao since 1963. She has dedicated her life to the site, and her unstinting support of the partnership with the GCI provides a constant source of guidance. A core member in the China Principles project, which has worked at other large World Heritage sites such as Chengde (the Qing dynasty summer resort) and Qufu (Confucius's birthplace), Director Fan has stated, "the joint Dunhuang Academy-Getty Conservation Institute work in Cave 85 is integral with the approach to the conservation of this large site of Mogao. Management according to principles that preserve the site's cultural values is now ever more important, as China develops and the pressures of tourism increase. We must succeed in our duty to keep intact the historical record and the sublime beauty of Mogao."

Neville Agnew is group director of Information & Communications at the GCI.

Wall Paintings Conservation at Mogao

by Francesca Piqué, Shin Maekawa, and Michael Schilling

Since October 1997, the GCI has been working with the Dunhuang Academy on a wall paintings conservation project at the Mogao grottoes. The objective is to identify and address urgent conservation problems affecting the wall paintings, while following the methodology for the conservation and management of cultural heritage sites being developed for China in a collaborative project between China's State Administration for Cultural Heritage, the GCI, and the Australian Heritage Commission. This methodology encompasses a statement of the cultural significance of the cave, condition documentation of the paintings, scientific investigations of environment and materials, and development of treatment strategies.

Cave 85, a large late-Tang dynasty cave, was selected as a model case study. The cave, with 16 large illustrated sutras in the main chamber, was completed in 866 for the Zhai family of the region.

The project's interdisciplinary team is composed of conservators, scientists, engineers, art historians, technical photographers, and draftspersons. The Dunhuang Academy brings to the collaboration long and extensive experience with the preservation of the wall paintings at Mogao, while the GCI's contribution includes expertise in project management and conservation science.

The rock temples of the Mogao grottoes were literally carved into a cliff face of soft conglomerate rock. The temple walls were plastered over with a mixture of clay and plant fiber, and the paintings were executed as line drawings in black ink on a layer of fine plaster covering the clay, then filled in with bright mineral colors.

For centuries the paintings have suffered deterioration of various kinds, from flaking and peeling of the paint layer to progressive loss of adhesion between the rock conglomerate and the clay-based plasters. The latter problem has resulted in the delamination of the painted plasters from their support—a problem common to other sites near Dunhuang and on the ancient Silk Road. Large areas of the paintings have been lost, as the delamination finally leads to the collapse and fall of the painted plaster. Since 1943 the Dunhuang Academy has addressed this problem by anchoring the plaster to the rock conglomerate with iron bolts and, more recently, by using liquefied earth-based grouts.

A detail of a painting in Cave 85 of Buddha and bodhisattvas. Photo: Sun Hong Cai.

However, the deterioration mechanisms have never been studied rigorously, in a way that would lead to the development of conservation and maintenance solutions. The conservation problems may be related to environmental conditions at the site, as well as to the original painting materials and techniques. While these problems may never be completely eliminated, understanding the causes and processes—in particular the role of water and soluble salts—is the basis for developing measures to reduce the rate of deterioration and ameliorate the situation.

Another conservation problem being addressed is the evaluation of methods for soot removal from the delicate and water-sensitive paintings. Traditional poulticing, as well as more sophisticated gel and laser cleaning techniques, will be tested.

This project is structured in phases—assessment, planning, testing, and implementation. The project team members work in small groups (conservation, documentation, analytical studies, and environmental monitoring) on specific parts of each phase; they are nearing completion of the assessment phase. The paintings' composition (pigments, binder, and stratigraphy), their current state of preservation, and the climatic environment inside and surrounding the cave, as well as the site's complex history, are being examined in order to reconstruct and determine the processes and causes of damage. In this phase, several analytical and environmental studies—such as the thorough examination and detailed recording of the wall paintings' condition and the monitoring of moisture movements in the conglomerate substrate—are being carried out. The design of the conservation plan will be developed jointly with Dunhuang Academy staff, who will undertake most of the actual interventions, once the project has been completed in 2002.

Francesca Piqué, project specialist, Shin Maekawa, senior scientist, and Michael Schilling, associate scientist, are members of the GCI's team working on the Mogao project.

A cross section of Cave 85 at the Mogao grottoes, where the GCI and the Dunhuang Academy are collaborating on a wall paintings conservation project. Nearly all of the 350 square meters of wall surface within the cave are covered with wall paintings.