Seventeen years ago this week, in a rain-sodden ceremony of pomp and solemnity, the Union Jack was lowered over Hong Kong for the last time and the colony was handed back to Beijing. Chris Patten choked back tears as he made his final address before an assembled gathering of British dignitaries that included Prince Charles and Tony Blair, then prime minister. “I am the 28th governor, the last governor,” Mr Patten said. “Now Hong Kong people are to run Hong Kong. That is the promise and that is the unshakeable destiny.”

Today, many in Hong Kong are wondering whether that promise and that destiny are beginning to look shaky. Hong Kong is facing arguably its worst political crisis since the handover, as pro-democracy activists and the Communist party in Beijing come into conflict over how the former colony should be run.

Under the so-called Joint Declaration, which was later crystallised in the Basic Law – Hong Kong’s “mini-constitution” – Beijing promised to preserve freedoms that were absent on the mainland: the freedom to demonstrate, freedom of the press and the independence of the judiciary on which the city’s status as an international financial centre rests.