When being tried in 2009 on charges of inciting subversion of state power for helping write Charter 08 - a pro-democracy manifesto calling for an end to one-party rule -Liu reaffirmed: “I have no enemies and no hatred."
He was sentenced to 11 years in prison that same year, drawing protests from the United States, many European governments and rights groups, which condemned the stiff sentence and called for his early release.
Liu won the Nobel Peace Prize in 2010.
Liu, 61, died on Thursday of multiple organ failure, the government of the northeastern Chinese city of Shenyang said. He was being treated in a hospital there, having been admitted in June after being diagnosed with late-stage liver cancer.
His wife, Liu Xia, had told Reuters previously that her husband wanted to dedicate the Nobel prize to those who died in the 1989 Tiananmen crackdown.
“He said this prize should go to all the victims of 4 June," Liu Xia said, after she was allowed to visit him in jail following the announcement of the prize.
“He felt sad, quite upset. He cried. He felt it was hard to deal with."
Liu Xia had been living under house arrest since her husband won the Nobel prize, but had been allowed to visit him in prison about once a month. She suffers from depression.
She was allowed to be with him in the hospital where he spent his last days.
Liu had been a thorn in Beijing’s side since 1989, when he helped negotiate a deal to allow protesters to leave Tiananmen Square before troops and tanks rolled in.
“Using the law to promote rights can only have a limited impact when the judiciary is not independent," Liu told Reuters in 2006, when he was under house arrest, in comments typical of those that have angered the government.
Charter 08 alarmed the Communist Party more for the 350 signatures —dignitaries from all walks of life – he collected than its content, political analysts said.
The manifesto was modelled on the Charter 77 petition that became a rallying call for the human rights movement in communist Czechoslovakia in 1977.
Liu had ceaselessly campaigned for the rights of the Tiananmen Mothers of victims of the crackdown.
He was much better known abroad than at home due to a government ban on internet and state media discussion of the Tiananmen protests, and of him, aside from the odd editorial condemning him.
Liu was considered a moderate by fellow dissidents and international rights groups. But they say the Communist Party is insecure and paranoid, fearing anyone or anything it perceives as a threat to stability.
In 2003, Liu wrote an essay, calling for the embalmed corpse of Chairman Mao Zedong to be removed from a mausoleum on Tiananmen Square. Mao is still a demigod to many in China.
Over the years, Liu won numerous human rights and free speech awards from organisations including Reporters Without Borders, Human Rights Watch and Hong Kong’s Human Rights Press Awards.
His books have been published in Germany, Japan, the United States, Hong Kong and Taiwan.
Hero to some, traitor to others
A hero to many in the West, Liu was branded a traitor by Chinese nationalists.
He had come under fire from nationalists for his comments in a 2006 interview with Hong Kong’s now-defunct Open magazine in which he said China would “need 300 years of colonisation for it to become like what Hong Kong is today".
The government considered him a criminal.
“For Liu Xiaobo, whatever the United States says or does is right, and whatever the Communist Party says or does is wrong," a source with ties to the leadership said.
“It’s too absolute," said the source, who declined to be identified.
Liu’s critics were suspicious of the motives of the Nobel Peace Prize committee, noting that Liu praised the US invasions of Iraq and Afghanistan.
He had also been taken to task domestically because non-government organisations he headed received funding from the US National Endowment for Democracy.
The third of five boys, Liu was born in Changchun, capital of the northeastern province of Jilin, on 28 December 1955.
His father, Liu Ling, taught Chinese literature at Northeast Normal University. His mother worked at a kindergarten affiliated with the university.
In 1970, at age 15, Liu was with his parents when they were sent to a labour camp in the region of Inner Mongolia at the height of the Cultural Revolution.
Liu worked briefly as a plasterer at a state-owned construction company in Changchun in 1976. After the Cultural Revolution, China resumed national university entrance examinations which Liu passed.
He earned his bachelor’s degree in Chinese literature from Jilin University and obtained his master’s and doctorate degrees from Beijing Normal University.
Liu had been in and out of prison and labour camps four times, excluding brief periods of house arrest ahead of politically sensitive anniversaries.
His first brush with incarceration came after the Tiananmen crackdown in 1989, when he spent 18 months at the notorious Qincheng penitentiary for political prisoners.
Liu was charged with counter-revolutionary propaganda and incitement, but a Beijing court exempted him from criminal action because he had negotiated with martial-law troops for student protesters to leave the square before tanks rolled in.
Police held him without charge on the outskirts of Beijing between May 1995 and January 1996, for drafting and circulating a petition calling for democracy and rule of law in the run-up to the sixth anniversary of the Tiananmen crackdown.
Liu Xiaobo married Liu Xia in 1997, during his three years of “re-education" at a labour camp in the northeastern city of Dalian. China abolished the extrajudicial administrative form of punishment in 2013. Reuters