The trial caps Hong Kong's effort to pursue those who encouraged the demonstrations, which sought the open nomination of candidates for what was supposed to be the first direct election of the city's leader. The protests focused the world's attention on Chinese efforts to constrain the local democracy movement, especially after police took the unprecedented step of firing tear gas at mostly student demonstrators, who defended themselves with umbrellas.

While Tai, 54, was a leading advocate for adopting Occupy Wall Street tactics and shutting down the city's financial centre, the first demonstrations were kicked off by high school and university students.

Leaders of the student groups, including Joshua Wong and Nathan Law, were sentenced to up to eight months in jail in 2017 for storming a government compound and triggering what also became known as the "Umbrella Movement". An earlier sentence of community service was overturned by a higher court after being deemed too light.

The government arrested more than 1,000 people during and after the sit-ins, which ended without securing any pledges to amend the Chinese government's framework for the 2017 chief executive's election. Instead, Chief Executive Carrie Lam was selected – like her predecessors – by a 1,200-member election committee stacked with Beijing loyalists.

The so-called "Umbrella Nine" on Tuesday faced counts of conspiracy to commit public nuisance, incitement to commit public nuisance and incitement to incite public nuisance, three colonial-era criminal provisions. All had pleaded not guilty.

"No matter what happens today, I have the confidence many people today will be together," Tai told a crowd of supporters before the hearing. "We'll continue to strive for Hong Kong's democracy. We'll persist on and we'll not give up."

The ruling Communist Party has since stepped up efforts to rein in what its leader views as some of the more radical element of Hong Kong's pro-democracy camp, including a small independence movement that gained momentum in the aftermath of Occupy. China pledged to maintain the city's free speech protections, independent judiciary and capitalist financial system before regaining it from the UK in 1997.

Bloomberg