A while ago, I saw a couple of demonstrations in Hong Kong staged by followers of Falun Gong, a spiritual movement branded an “evil cult” by the central government. The several hundred marchers were peaceful, with most of the aggression coming from their hecklers and drivers inconvenienced by the closed roads. The jury may still be out on Falun Gong’s alleged malignancy, but there is no doubt that the mass movement is well organised and has deep pockets, and it is this that worries Beijing more than anything else.

Armed revolts under the banner of religion have been a bane of rulers throughout China’s history and they could also occur in relatively good times. In 1420, during the reign of the Ming dynasty’s Yongle Emperor, when much of China was peaceful and prosperous, a young Shandong woman called Tang Sai’er, who claimed to be Buddha’s mother, managed to raise thousands of her devotees in revolt against the government.

Although the rebellion was put down within a month, thousands of government soldiers were killed in the fighting. Rare among defeated rebel leaders, Tang evaded capture. Believing that she was living incognito as a Buddhist nun or Taoist priestess, the authorities rounded up all the nuns and priestesses in Shandong for questioning but they couldn’t find her. What became of Tang remains a mystery.