The 13 appellants, aged between 27 and 69, are from across the political spectrum in Hong Kong's once-vibrant opposition and include former lawmakers, district councillors and young activists.

They were among 45 opposition figures sentenced in November, with their jail terms ranging from four years and five months to seven years and nine months for "conspiracy to subvert the state power" through an unofficial primary election.

AFP looks at some of them:

- Leung Kwok-hung, 69 -

The avid Marxist and ex-lawmaker -- better known as "Long Hair" -- has been in and out of prison for his activism, first against colonial Britain and then China's increasingly authoritarian rule.

He and his wife, fellow activist Chan Po-ying, co-founded the League of Social Democrats as a more radical wing of the pro-democracy camp, advocating street action.

The group announced its disbandment last month, citing "immense political pressure".

Leung was jailed for six years and nine months.

- Owen Chow, 28 -

Chow, a political newcomer who tried to run for the legislature, was jailed for seven years and nine months -- the heaviest penalty among the 13 appellants.

Judges said Chow, who studied nursing at university, was a member of the "localist resistance group" that believed in defending Hong Kong's local identity and autonomy from Chinese encroachment.

He was an initiator of "Inked Without Regret", a 2020 declaration seen by the court as evidence of the subversive intentions of its signatories.

- Gwyneth Ho, 34 -

Ho, a former journalist, became a hero to the democracy movement for her hours of live reporting on large, and sometimes violent, pro-democracy protests in 2019.

She captured footage of government supporters attacking democracy activists at a train station, broadcasting even as the assailants turned on her.

Judges sentenced her to seven years in prison, saying she held "the most radical political view" of uprooting Hong Kong's political structure.

Ho criticised the trial last year as taking place in a "comical", "1984-esque reality".

- Gordon Ng, 46 -

Ng, an Australian citizen, was sentenced to seven years and three months in prison.

He launched a publicity campaign, mostly on social media, to raise the profile of the pro-democracy camp's informal election, although he did not become a candidate.

Australian Foreign Minister Penny Wong said in November that Canberra was "gravely concerned" about the jailings of Ng and other Hong Kong activists.

- Lam Cheuk-ting, 48 -

Lam, a former opposition lawmaker, worked as an investigator in Hong Kong's anti-corruption watchdog before entering politics.

He and another appellant, Helena Wong, belonged to Hong Kong's oldest pro-democracy political party -- the Democratic Party -- which began its formal dissolution process this year.

Lam was jailed for six years and nine months.