After new law begins, Hong Kong marks handover

The contentious law will punish crimes of secession, subversion, terrorism and collusion with foreign forces with up to life in prison, heralding a more authoritarian era for China's freest city.

On July 1 last year, hundreds of protesters stormed the city's legislature to protest against a now-scrapped bill that would have allowed extraditions to mainland China, trashing the building in a direct challenge to authorities in Beijing.

Those protests evolved into calls for greater democracy, paralysing parts of the city and paving the way for Beijing to directly impose national security law on Hong Kong, a move that has drawn condemnation from some Western governments.