He rose to riches in Hong Kong. Now he’s a symbol of China’s crackdown.

He rose from child laborer to clothing tycoon and media baron, living in a colonial mansion filled with books and flowers. His Apple Daily newspaper celebrated the city’s freewheeling outlook with reviews of brothels alongside full-throated denunciations of China’s Communist Party.

When protesters, Lai among them, tried to secure democracy for Hong Kong and stop Beijing from tightening its grip, only to face exile or imprisonment, the self-made millionaire became a symbol of the city’s new era. Now, press freedom is curtailed, a draconian national security law reigns and opponents of the Communist Party risk being crushed.

Lai’s rags-to-riches-to-prison story mirrors Hong Kong’s own path from fishing outpost to neon-lit hive of unbridled commerce and, more recently, battleground for Chinese leader Xi Jinping’s determination to stamp out dissent.

Lai “always said Hong Kong gave me everything," said his youngest son, Sebastien Lai. “He’s a self-made man, but at some point he realized he couldn’t have had what he had if it wasn’t for Hong Kong."

If Hong Kong helped make Lai, it is now trying to break him.

He has been in custody for nearly four years, having completed four sentences for his protest roles and working through another, for a 2022 fraud conviction, that lasts into 2028. He now faces charges of publishing seditious materials and violating the national security law that Beijing imposed in 2020 in response to democracy protests.

To all charges, Lai has pleaded not guilty. He is expected to testify in his own defense when his current trial resumes on Wednesday, at a court complex a few blocks from the street where he worked in a glove factory after first arriving in the city as a boy.

If convicted, Lai, who turns 77 in December, faces up to life in prison.

“The crackdown on him sends a signal that Hong Kong’s democratic movement, that freedom of the press and free elections are done with," said Ho-fung Hung, a political economy professor at Johns Hopkins.

The U.S., U.K. and European Parliament have called for the release of Lai, who is a British citizen. During the campaign, President-elect Donald Trump pledged to make that happen. “One hundred percent, I’ll get him out," Trump said.

Hong Kong’s government said Sunday that foreign individuals and entities should respect its judicial system, and not interfere.

Early lessons

Lai was born to a prosperous family that lost its wealth after the Communist Party’s takeover in 1949.

His father had left and his mother was repeatedly detained for re-education, forcing him at age 7 to care for himself and two sisters. He started by selling scrap metal. He later worked as a hawker, learning to price lighters and candy cheaply so he could make quick sales.

While Lai was working as a baggage handler in a train station, a traveler from Hong Kong tipped him with a half-eaten chocolate bar—a luxury he hadn’t previously tasted. He vowed to make his way to the British colony.

Lai was smuggled to Hong Kong in the hold of a fishing boat, seawater mixed with vomit sloshing in the bilge, he later wrote. He had lost his shoes and was barefoot when he finally arrived.

“I was 12 years old and had had a brush with hell," he wrote. “Stepping onto the beach, I had already grown up."

An aunt took him to a glove factory in Sham Shui Po, one of the city’s poorest districts, where he spent his first night in Hong Kong sleeping on a packing table. The next morning, he reveled in a simple breakfast of congee, rice noodle rolls and fried dough.

“The people here are poor," he later wrote, “but the open and cheerful atmosphere is full of opportunities and makes people feel hopeful."

Business savvy

Lai rose to factory manager and in his mid-20s bought a factory of his own, producing sweaters for international labels such as JCPenney and The Limited. His sense of the market had been honed from his childhood days as a hawker.

He was “an extraordinarily creative entrepreneur," said Mark Clifford, an ex-journalist in Hong Kong and former board member of Lai’s media company Next Digital, who has written a forthcoming biography of Lai, titled “The Troublemaker."

Lai built Giordano, a casual-clothing retailer named after a New York pizza parlor. The company grew in Hong Kong and, later, mainland China and across Asia.

Giordano, with its range of brightly colored polo shirts, was an inspiration for Uniqlo, whose founder, Tadashi Yanai, sought advice from Lai in the 1980s as he built the Japanese retail company.

Lai’s political activism began during democracy protests in China in 1989, when he printed T-shirts in support of the movement.

“I didn’t feel anything about China until Tiananmen Square happened," he said in “The Hong Konger," a 2023 documentary of his life. “All of a sudden it’s like my mother was calling in the darkness of the night, and my heart opened up."

After Beijing violently crushed the democracy protests, Lai began to view media as the way to force China to open up.

In 1990, Lai founded Next Magazine, a mix of gossip, politics and finance. Five years later, he started Apple Daily, which quickly became one of the city’s most-read daily newspapers and a cheerleader for laissez-faire economics and political freedom.

Lai’s news outlets relentlessly criticized the Communist Party and its leadership. In a 1994 column in Next, Lai denounced Li Peng, China’s premier and a leading figure in the 1989 crackdown, calling him a “turtle’s egg with zero IQ."

In response, the Chinese government shut Lai’s Giordano store in Beijing, threatening the company’s plans to expand in China.

He sold off his Giordano stake in 1996 for an estimated 1.5 billion Hong Kong dollars, equivalent to $190 million, to focus on media. Through the media, Lai could help people pursue something he deeply admired: freedom.

His decision to stand and fight set the course for a long-running battle with Beijing.

Lai’s publications reveled in the openness of Hong Kong and later Taiwan, where he opened more outlets. An animation studio became a global online sensation in 2009 for its bawdy recaps of news stories, which often represented China as a murderous giant panda.

Sometimes Lai’s publications went too far. Easy Finder, a tabloid magazine, was closed and reopened under a new name in 2007 after it published dressing room photos of a pop singer that triggered protests and fines for violating obscenity laws.

No regrets

In the early 2000s, Hong Kong became the front line in the fight for democracy in China. Lai helped fund a successful campaign in 2003 to block national security legislation that would have given the government vast powers to punish vaguely defined acts of treason and subversion. Apple Daily printed placards that protesters carried in a huge march that year.

Lai joined pro-democracy protests in 2014, camping out with protesters who occupied streets near the city’s legislature and other key spots.

“I have no regrets," he wrote after legal injunctions forced the protesters to retreat, “because the struggle is just beginning and there is still a long way to go."

From 1989 until he was jailed in 2020, Lai contributed more than $140 million to pro-democracy causes, Clifford writes in his new book.

When the large protests broke out in 2019, Lai and his outlets gave their support. The demonstrations began over a plan to allow extraditions to mainland China, then expanded to encompass several demands, including a longstanding goal of full local democracy.

Lai joined peaceful marches, for which he was later imprisoned, but he blanched at protest violence and frequent clashes with police, warning that the Communist Party and its allies would always win a battle of force.

The crackdown that followed was severe, with more than 10,000 people arrested. The city’s pro-democracy camp was crushed, its leading politicians and activists imprisoned or exiled. Apple Daily was forced to shut down and other news outlets followed.

Even before he was charged under the security law that Beijing imposed on the city in 2020, Lai said he felt he was a likely target. He chose not to leave Hong Kong, he told interviewers at the time, because he felt an obligation to continue helping the cause of freedom in Hong Kong.

In prison, Lai, a devout Catholic, has spent time studying the Bible and other religious works, according to people who have been in touch with him. He draws religious images, such as Christ on the cross. In letters to friends and colleagues, he said that he found meaning in the hardship of imprisonment.

“I choose truth instead of a lie and pay the price," he wrote in a letter published in the U.K. journal Index on Censorship. “Luckily God has made this price a grace in disguise. I am so grateful."

Write to Austin Ramzy at austin.ramzy@wsj.com