The Mogao Caves, also known as the Thousand Buddha Grottoes or Caves of the Thousand Buddhas, form a system of 500 temples southeast of the center of Dunhuang, an oasis located at a religious and cultural crossroads on the Silk Road, in Gansu province, China. The caves may also be known as the Dunhuang Caves; however, this term is also used as a collective term to include other Buddhist cave sites in and around the Dunhuang area, such as the Western Thousand Buddha Caves, Eastern Thousand Buddha Caves, Yulin Caves, and Five Temple Caves. The caves contain some of the finest examples of Buddhist art spanning a period of 1,000 years. The first caves were dug out in 366 CE as places of Buddhist meditation and worship; later the caves became a place of pilgrimage, and caves continued to be built at the site until the 14th century. The Mogao Caves are the best known of the Chinese Buddhist grottoes and, along with Longmen Grottoes and Yungang Grottoes, are one of the three famous ancient Buddhist sculptural sites of China.
An important cache of documents was discovered in 1900 in the so-called "Library Cave", which had been walled-up in the 11th century. The contents of the library were subsequently dispersed around the world, and the largest collections are now found in Beijing, London, Paris and Berlin, and the International Dunhuang Project exists to coordinate and collect scholarly work on the Dunhuang manuscripts and other material. The caves themselves are now a popular tourist destination, but the number of visitors has been capped to help with the preservation of the caves.
Etymology
The caves are commonly referred to in Chinese as the Caves of the Thousand Buddhas (), a name that some scholars have speculated to have come from the legend of its founding, when a monk Yuezun had a vision of a thousand Buddhas at the site. This name, however, may have come from the large number of Buddha figures at the site, or the miniatures figures painted on the walls of these caves as these figures are called "thousand Buddhas" colloquially. The name Mogao Caves () was used in the Tang dynasty, where 'Mogao' refers to an administrative district at the site during the Tang dynasty. Mogao may mean "peerless" (literally "none higher", where "mo" means "none", and "gao" means "high"); an alternative reading may be "high in the desert" if "mo" is read as a variant of the Chinese term for "desert". Mogao is also used as the name of a modern town that is administered by Dunhuang city: Mogao Town (). The Mogao Caves are also often referred to as the Dunhuang Caves after the nearest city Dunhuang, which means "blazing beacon" as beacons were used at the frontier outpost to warn of attacks by nomadic tribes. The term Dunhuang Caves however is also used in a broader sense as a collective term for all the caves found in or around the Dunhuang area.
History
Dunhuang was established as a frontier garrison outpost by the Han dynasty Emperor Wudi to protect against the Xiongnu in 111 BC. It also became an important gateway to the West, a centre of commerce along the Silk Road, as well as a meeting place of various people and religions such as Buddhism. The Mogao Caves near Dunhuang were first constructed in the 4th century AD and were used as a site of Buddhist worship and pilgrimage. The caves contain over 400,000 square feet of frescoes and sculptures, making them one of the largest repositories of Buddhist art in the world.
The construction of the Mogao Caves is generally taken to have begun sometime in the fourth century AD, when Dunhuang was under control of the Former Liang dynasty. According to a book written during the reign of Empress Wu Zetian, Fokan Ji (, An Account of Buddhist Shrines) by Li Junxiu (), a Buddhist monk named Le Zun (, which may also be pronounced Yuezun) had a vision of a thousand Buddhas bathed in golden light at the site in 366 AD, inspiring him to build a cave here. The story is also found in other sources, such as in inscriptions on a stele in cave 332; an earlier date of 353 however was given in another document, Shazhou Tujing (, Geography of Shazhou). He was later joined by a second monk Faliang (), and the site gradually grew, by the time of the Northern Liang a small community of monks had formed at the site. The caves initially served only as a place of meditation for hermit monks, but developed to serve the monasteries that sprang up nearby.
The earliest decorated Mogao Caves remaining to this day (caves 268, 272 and 275), were built and decorated in the Northern Liang period between 419 and 439 CE, before the invasion of the Northern Wei. They share many stylistic characteristics in common with some of the Kizil Caves, such as Cave 17. Members of the ruling family of Northern Wei and Northern Zhou then constructed many caves here, and it flourished in the short-lived Sui dynasty. By the Tang dynasty, the number of caves had reached over a thousand.
thumb|left|Details of painting of the meeting of [[Manjusri and Vimalakirti. Cave 159.]]
By the Sui and Tang dynasties, Mogao Caves had become a place of worship and pilgrimage for the public. From the 4th until the 14th century, caves were constructed by monks to serve as shrines with funds from donors. These caves were elaborately painted, the cave paintings and architecture serving as aids to meditation, as visual representations of the quest for enlightenment, as mnemonic devices, and as teaching tools to inform those illiterate about Buddhist beliefs and stories. The major caves were sponsored by patrons such as important clergy, local ruling elite, foreign dignitaries, as well as Chinese emperors. Other caves may have been funded by merchants, military officers, and other local people such as women's groups.
During the Tang dynasty, Dunhuang became the main hub of commerce of the Silk Road and a major religious centre. A large number of the caves were constructed at Mogao during this era, including the two large statues of Buddha at the site, the largest one constructed in 695 following an edict a year earlier by Empress Wu Zetian to build giant statues across the country. The site escaped the persecution of Buddhists ordered by Emperor Wuzong in 845 as it was then under Tibetan control. During this time of Tibetan domination (787–848), Dunhuang was not only occupied but also became part of a huge administrative system that was based on the Tibetan Empire. The region was ruled by a system called "khrom," which merged Tibetan political power with Han administrative methods. Tibetan officials and local Han elites made up the ruling body. As a frontier town, Dunhuang had been occupied at various times by other non-Han Chinese people. After the Tang dynasty, the site went into a gradual decline, and construction of new caves ceased entirely after the Yuan dynasty. By then Islam had conquered much of Central Asia, and the Silk Road declined in importance when trading via sea-routes began to dominate Chinese trade with the outside world. During the Ming dynasty, the Silk Road was finally officially abandoned, and Dunhuang slowly became depopulated and largely forgotten by the outside world. Most of the Mogao caves were abandoned; the site, however, was still a place of pilgrimage and was used as a place of worship by local people at the beginning of the twentieth century when there was renewed interest in the site.
Discovery and revival
thumb|right|Bodhisattva leading a lady [[donor portrait|donor towards the Pure Lands. Painting on silk (Library Cave), Late Tang.]]
During late nineteenth century and early twentieth century, Western explorers began to show interest in the ancient Silk Road and the lost cities of Central Asia, and those who passed through Dunhuang noted the murals, sculptures, and artifacts such as the Stele of Sulaiman at Mogao. There is an estimated half a million square feet of religious wall murals within the caves. The biggest discovery, however, came from a Chinese Taoist abbot named Wang Yuanlu who had appointed himself guardian of some of these temples around the turn of the century and tried to raise funds to repair the statues.
Some of the caves had by then been blocked by sand, and Wang set about clearing away the sand and made an attempt at restoration of the site. In one such cave, on 25 June 1900, Wang followed the drift of smoke from a cigarette, and discovered a walled up area behind one side of a corridor leading to a main cave. Behind the wall was a small cave stuffed with an enormous hoard of manuscripts. In the next few years, Wang took some manuscripts to show to various officials who expressed varying level of interest, but in 1904 Wang re-sealed the cave following an order by the governor of Gansu concerned about the cost of transporting these documents.
thumb|200px|left|Abbot [[Wang Yuanlu, discoverer of the hidden Library Cave]]
Words of Wang's discovery drew the attention of a joint British/Indian group led by the Hungarian-born British archaeologist Aurel Stein who was on an archaeological expedition in the area in 1907. Stein negotiated with Wang to allow him to remove a significant number of manuscripts as well as the finest paintings and textiles in exchange for a donation to Wang's restoration effort. He was followed by a French expedition under Paul Pelliot who acquired many thousands of items in 1908, and then by a Japanese expedition under Otani Kozui in 1911 and a Russian expedition under Sergei F. Oldenburg in 1914. A well-known scholar Luo Zhenyu edited some of the manuscripts Pelliot acquired into a volume which was then published in 1909 as "Manuscripts of the Dunhuang Caves" ().
Stein and Pelliot provoked much interest in the West about the Dunhuang Caves. Scholars in Beijing, after seeing samples of the documents in Pelliot's possession, became aware of their value. Concerned that the remaining manuscripts might be lost, Luo Zhenyu and others persuaded the Ministry of Education to recover the rest of the manuscripts to be sent to Peking (Beijing) in 1910. However, not all the remaining manuscripts were taken to Peking, and of those retrieved, some were then stolen. Rumours of caches of documents taken by local people continued for some time, and a cache of documents hidden by Wang from the authorities was later found in the 1940s. In 1924, American explorer Langdon Warner removed a number of murals as well as a statue from some of the caves. In 1939 Kuomintang soldiers stationed at Dunhuang caused some damage to the murals and statues at the site.
The situation improved in 1941 when, following a visit by Wu Zuoren to the site the previous year, the painter Zhang Daqian arrived at the caves with a small team of assistants and stayed for two and a half years to repair and copy the murals. He exhibited and published the copies of the murals in 1943, which helped to publicize and give much prominence to the art of Dunhuang within China. Historian Xiang Da then persuaded Yu Youren, a prominent member of the Kuomintang (Chinese Nationalist Party), to set up an institution, the Research Institute of Dunhuang Art (which later became the Dunhuang Academy), at Mogao in 1944 to look after the site and its contents. In 1956, the first Premier of the People's Republic of China, Zhou Enlai, took a personal interest in the caves and sanctioned a grant to repair and protect the site; and in 1961, the Mogao Caves were declared to be a specially protected historical monument by the State Council, and large-scale renovation work at Mogao began soon afterwards. The site escaped the widespread damage caused to many religious sites during the Cultural Revolution.
Today, efforts are continuing to conserve and research the site and its content. The Mogao Caves became one of the UNESCO World Heritage Sites in 1987.
The Dunhuang Academy entered a period of "scientific conservation" for the Mogao Caves in the 1980s and began exploring "digital conservation" as early as 1993. Since 2010, it has completed photographic acquisition of 120 caves, image processing of 40 caves, panoramic roaming of 120 caves, and 3D reconstruction of 20 painted sculptures in the Mogao Caves. The Dunhuang Academy also introduced I-m-Cave, a multi-touch desktop system for virtual tours of the Mogao Caves, which presents a relationship between currently damaged artifacts and their virtual restored versions that cannot be experienced during a real tour.
The Library Cave
thumb|280px|Picture of Cave 16, by Aurel Stein in 1907, with manuscripts piled up beside the entrance to Cave 17, the Library Cave, which is to the right in this picture.
Cave 17, discovered by Wang Yuanlu in the early 1900s, came to be known as the Library Cave. It is located off the entrance leading to cave 16 and was originally used as a memorial cave for a local monk Hongbian on his death in 862. Hongbian, from a wealthy Wu family, was responsible for the construction of cave 16, and the Library Cave may have been used as his retreat in his lifetime. The cave originally contained his statue which was moved to another cave when it was used to keep manuscripts, some of which bear Hongbian's seal. A large number of documents dating from 406 to 1002 were found in the cave, heaped up in closely packed layers of bundles of scrolls. In addition to the 1,100 bundles of scrolls, there were also over 15,000 paper books and shorter texts, including a Hebrew penitential prayer (selichah) (see Dunhuang manuscripts). It's estimated that 50,000 ancient documents were discovered inside on topics of literature, philosophy, art and medicine.
The Library Cave was walled off sometime early in the 11th century. Another suggestion is that the cave was simply used as a book storehouse for documents which accumulated over a century and a half, then sealed up when it became full. Others, such as Pelliot, suggested an alternative scenario, that the monks hurriedly hid the documents in advance of an attack by invaders, perhaps when Xi Xia invaded in 1035. This theory was proposed in light of the absence of documents from Xi Xia and the disordered state in which Pelliot found the room (perhaps a misinterpretation because unbeknownst to him the room was disturbed by Stein months before). Another theory posits that the items were from a monastic library and hidden due to threats from Muslims who were moving eastward. This theory proposes that the monks of a nearby monastery heard about the fall of the Buddhist kingdom of Khotan to Karakhanids invaders from Kashgar in 1006 and the destruction it caused, so they sealed their library to avoid it being destroyed. Another possible theory posits that to save the manuscripts from a coming "Age of Decline", the Library Cave was sealed to prevent this from occurring.
The date of the sealing of the cave continued to be debated. Rong (2000) provided evidence to support 1002 as the date for sealing the cave, It is difficult to determine the state of the materials found since the chamber was not opened "under scientific conditions", so critical evidence to support dating the closure was lost. The manuscripts found in the Library Cave include the earliest dated printed book, the Diamond Sutra from 868, which was first translated from Sanskrit into Chinese in the fourth century. These scrolls also include manuscripts that ranged from the Christian Jingjiao Documents to the Dunhuang Go Manual and ancient music scores, as well as the image of the Chinese astronomy Dunhuang map. These scrolls chronicle the development of Buddhism in China, record the political and cultural life of the time, and provide documentation of mundane secular matters that gives a rare glimpse into the lives of ordinary people of these eras.
The manuscripts were dispersed all over the world in the aftermath of the discovery. Stein's acquisition was split between Britain and India because his expedition was funded by both countries. Stein had the first pick and he was able to collect around 7,000 complete manuscripts and 6,000 fragments for which he paid £130, although these include many duplicate copies of the Diamond and Lotus Sutras. Pelliot took almost 10,000 documents for the equivalent of £90, but, unlike Stein, Pelliot was a trained sinologist literate in Chinese, and he was allowed to examine the manuscripts freely, so he was able to pick a better selection of documents than Stein. Pelliot was interested in the more unusual and exotic of the Dunhuang manuscripts, such as those dealing with the administration and financing of the monastery and associated lay men's groups. Many of these manuscripts survived only because they formed a type of palimpsest whereby papers were reused and Buddhist texts were written on the opposite side of the paper. Hundreds more of the manuscripts were sold by Wang to Otani Kozui and Sergei Oldenburg. Efforts are now underway to reconstitute the Library Cave manuscripts digitally, and they are now available as part of International Dunhuang Project.
In the B53 cave of the northern Mogao Grottoes, a two page four fold Syrian manuscript was discovered, which was identified by Professor Duan Qing of Peking University as part of the Bible's Psalms, with annotations in Uyghur script interspersed between the lines. This is the first time that a Syrian version of the "Psalms" has been discovered in a Buddhist cave in China, providing unprecedented textual evidence for studying the spread of the Eastern Christian sect of Nestorianism in Dunhuang during the Mongol Yuan period.