Rights groups and experts say the case is a pivotal free-speech test in Hong Kong, with organizations like Amnesty International and academic voices highlighting implications for political speech and historical memory.

The Tiananmen vigil, long a symbol of Hong Kong autonomy, was effectively curtailed during Covid-19 and the broader crackdown, culminating in the Alliance’s disbandment in 2021.

A landmark national security trial opens in Hong Kong for Chow Hang-tung and Lee Cheuk-yan, former leaders of the Hong Kong Alliance in Support of Patriotic Democratic Movements of China, who face incitement to subversion charges under the national security law.

The case alleges they incited others to organize or act through unlawful means with a view to subverting state power, carrying a potential maximum penalty of 10 years in prison.

This trial marks a high-profile test of Beijing’s security framework as the High Court hears a case tied to decades-long Tiananmen vigil activities led by the Alliance.

Rights organizations and international bodies criticize the prosecutions as silencing dissent, while Beijing defends the law as essential for peace and stability.

The case underscores tensions between Hong Kong’s former freedoms and Beijing’s security framework, noting that public discussion of Tiananmen remains restricted on the mainland.

Three government-vetted judges will preside over the 75-day trial, with footage from the Alliance’s activities presented as evidence, and officials insist the court will not become a tool of political suppression.

Crowds of supporters and family members gathered outside the courtroom, underscoring the ongoing political significance of the trial in relation to Hong Kong’s civil liberties promises.

Background shows the Alliance’s role in organizing the Tiananmen vigil, its 2021 disbandment, prior convictions for not providing information to authorities, and broader impacts of Hong Kong’s national security law on civil society.

The case is a major test of Hong Kong’s civil liberties and has attracted intense international attention.

(With inputs from agencies.)