Joshua Wong was the unlikely hero who helped lead a movement that inspired hundreds of thousands of Hong Kongers to take over the city's streets for two months in 2014 calling for fully free elections.
Scrawny, with gaunt features and a studious frown, the then 17-year-old spearheaded the mass "Umbrella Movement" protests, which were a reaction to restrictions from Beijing on how Hong Kong's next leader would be chosen.
Alongside fellow student leaders Nathan Law and Alex Chow, Wong's speeches and calls for civil disobedience electrified the crowds but the movement failed to win any concessions from China or Hong Kong's pro-Beijing leaders.
He captured the attention of the world in his casting as David against the Goliath of the Chinese Communist Party, and was hailed as one of the world's most influential figures by Time, Fortune and Foreign Policy magazines.
He even became the subject of Netflix documentary "Teenager vs Superpower", released in 2017.
Born to middle-class Christian parents Grace and Roger Wong, he began his life of activism aged just 13 with a protest against plans for a high-speed rail link between Hong Kong and the mainland.
At the age of just 15, Wong campaigned successfully for Hong Kong to drop a pro-China "National Education" program, rallying a crowd of 120,000 to blockade the city's parliament for 10 days.
In many ways he pioneered a protest method that has since been embraced by Hong Kong's protest movement -- seizing streets in non-violent civil disobedience -- after years of peaceful rallies failed to achieve much.
But he has paid for his activism. Prosecutors came after him and many of the Umbrella Movement's leaders.
- 'The city I love' -
In mid-May he was sentenced to two months on a contempt charge after pleading guilty to obstructing the clearance of a major protest camp in 2014.
He was also convicted in a second prosecution related to the storming of a government forecourt during the 2014 protests.
He spent some time behind bars for that case, but in the end the city's top court ruled that community service was sufficient punishment.
Alongside Nathan Law and Alex Chow he went on to found the political party Demosisto which campaigns for more self-determination for Hong Kong but not independence -- a clear red line to Beijing.
His demands have been both consistent and fairly simple: that Hong Kongers should get to decide their city's fate, not communist party officials in Beijing.
Since the end of the Umbrella Movement, he has been denied entry into Malaysia and Thailand, attacked in the street, and abused by pro-China protesters in Taiwan. But he has said he will fight on.
In an article written for Time Magazine from prison last week -- as historic protests gripped the city once more over an deeply divisive extradition law -- he wrote: "My lack of freedom today is a price I knew I would have to pay for the city I love."
He stepped back into the fray on Monday when authorities released him just one month into his prison term.
Authorities did not confirm whether the decision was procedural or a gesture to protestors.
He immediately called for Hong Kong's pro-Beijing leader Carrie Lam to step down over her role pushing for the controversial extradition bill and vowed to join the protests.
"She is no longer qualified to be Hong Kong's leader," Wong told reporters. "She must take the blame and resign, be held accountable and step down."
"After leaving jail today I will also fight with all Hong Kongers to oppose the evil China extradition law," he added.