Beijing serene in spring sunshine. Students gaily acting as traffic police. Normally surly bus conductors and shop assistants suddenly becoming models of politeness. Tiananmen Square a circus fairground of banners, tents and clapped out vehicles bringing exuberant demonstrators from across China.

In those two weeks 20 years ago – in that brief illusion of space created by the absence of all signs of authority when the Communist party and security forces seemed to have completely melted away – the People’s Republic finally appeared just that: a country run by the people for the people.