Construction of the Yungang Caves began in 453 AD, when Datong was the capital of the Northern Wei dynasty, and petered out around 525, after the centre of power moved to Luoyang. The caves were made by first hollowing out a section at the top of the cliff, then digging into the rock, down to the ground and out, leaving two holes, one above the other. As many as forty thousand craftsmen worked on the project, coming from as far as India and Central Asia, and there is much foreign influence in the carvings: Greek motifs (tridents and acanthus leaves), Persian symbols (lions and weapons), and bearded figures, even images of the Hindu deities Shiva and Vishnu, are incorporated among the more common dragons and phoenixes of Chinese origin. The soft, rounded modelling of the sandstone figures – China’s first stone statues – lining the cave interiors has more in common with the terracotta sculptures of the Mogao Caves near Dunhuang in Gansu, begun a few years earlier, than with the more linear features of Luoyang’s later limestone work. In addition, a number of the seated Buddhas have sharp, almost Caucasian, noses.
The caves’ present condition is misleading, as originally the cave entrances would have been covered with wooden facades, and the sculptures would have been faced with plaster and brightly painted; the larger ones are pitted with regular holes, which would once have held wooden supports on which the plaster face was built. Over the centuries, some of the caves have inevitably suffered from weathering, though there seems to have been little vandalism, certainly less than at Luoyang.
Today a 1km-long fragment of the original array survives, arranged in three clusters (east, central and west) and numbered east to west from 1 to 51. The earliest group is caves 16–20, followed by 7, 8, 9 and 10, then 5, 6 and 11 – the last to be completed before the court moved to Luoyang. Then followed 4, 13, 14 and 15, with the caves at the eastern end – 1, 2 and 3 – and cave 21 in the west, carved last.