Le Zun cuts the first cave at Mogao

The story is told on a stele set up in 698, in the reign of Empress Wu Zetian, to commemorate the cave shrine of a donor named Li (the stele of Li Kerang, from cave 332, now in the Dunhuang Academy). In the second year of the Jianyuan era of the Qin (366), it says, the monk Le Zun came to “this mountain” — the cliff at the eastern foot of Mount Mingsha, 25 km southeast of Dunhuang, where the caves are cut (some retellings place him at the foot of Mount Sanwei opposite) — saw a golden light in the form of a thousand Buddhas and made a cave there; after him the meditation master Faliang built another. Dunhuang then belonged to the Former Liang, the state of the Zhang family in Gansu; the stele dates the event by the era of the Former Qin, which annexed the region in 376.

The earliest decorated caves that survive date from half a century later: nos. 268, 272 and 275 are usually attributed to the Northern Liang period (419–439), though some scholars date them later. Cave-cutting went on through eleven periods down to the Yuan dynasty, and by the time of Wu Zetian there were more than a thousand cave chambers. Today 492 caves with murals and sculptures survive, with more than 45,000 m² of wall paintings and over 3,000 painted clay statues, and in 1900 a sealed library cave holding some 50,000 documents was discovered there. The founding date is not certain: 366 is the date usually accepted, but a Dunhuang manuscript (P.2691) puts the first caves in 353 and a late Tang inscription in cave 156 at the end of the Western Jin.