Liu Xiaobo (left) met his wife for the first time in months at his sentencing
There has been widespread condemnation of the jailing by China of leading dissident, Liu Xiaobo, for subversion.
The US, UN and EU were joined by human rights groups in a chorus of anger over Mr Liu's 11-year sentence.
The UN human rights commissioner said it was "extremely harsh", and cast an ominous shadow over China's commitments to protect human rights.
Mr Liu, 53, helped draft Charter 08, a petition urging political change in China. His wife said he would appeal.
Liu Xia was allowed to see her husband for the first time since March at Friday's sentencing in the Chinese capital, Beijing.
"We were able to meet for 10 minutes and we were all smiles when we spoke. I smiled so that he could be calm," she told AFP news agency.
Micky Bristow, BBC News, Beijing
Liu Xiaobo's sentence could have been worse - he could have been given a maximum of 15 years in prison but no-one is yet suggesting that the activist got off lightly.
Human rights groups and others with knowledge of China's legal system say this is a harsh sentence. Amnesty International said that according to their records this is the longest sentence handed down for this charge since 2003, perhaps longer.
China's Communist Party leaders appear to be sending a message to anyone else who might want to challenge their total grip on power: don't. Chinese people have been given many freedoms since reforms were first begun 30 years ago, but this sentence shows that they have only very limited political rights.
Mr Liu's lawyer said he had pleaded not guilty to charges of "inciting subversion of state power".
The verdict said Mr Liu "had the goal of subverting our country's people's democratic dictatorship and socialist system. The effects were malign and he is a major criminal," Reuters news agency reported.
Mr Liu has been in jail since 2008, after being arrested for writing a petition known as Charter 08.
It called for greater freedoms and democratic reforms in China, including an end to one-party rule.
The former university professor is a veteran of the 1989 Tiananmen Square democracy protests.
More than 300 international writers, including Salman Rushdie, Umberto Eco and Margaret Atwood, have called for his release.
Western diplomats and journalists were barred from attending the trial and sentencing.
But outside the Number One Intermediate People's Court, US embassy official Gregory May urged China to free Mr Liu immediately.
"Persecution of individuals for the peaceful expression of political views is inconsistent with internationally recognised norms of human rights," Mr May said.
Liu Xiaobo is a veteran of the 1989 Tiananmen Square protests
In Brussels, the EU presidency, currently held by Sweden, said it was "deeply concerned by the disproportionate sentence".
UN human rights commissioner Navi Pillay, in Geneva, said the case represented "a further severe restriction on the scope of freedom of expression in China".
Beijing has accused Washington and the EU of meddling.
Chinese foreign ministry spokeswoman Jiang Yu told reporters this week that statements from embassies calling for Mr Liu's release were "a gross interference of China's internal affairs".
Human rights organisations joined the outcry from diplomats; Reporters Without Borders branded the sentence "a disgrace".
US-based Human Rights Group and UK-based Amnesty International said the case was a warning to China's intellectuals and activists.
In Hong Kong, a group of around 50 people protested against the sentence.
Photos taken outside China's Liaison Office in Hong Kong showed three people being treated for injuries.
A security guard, a protester and a police officer were hurt during the demonstration, said the Associated Press news agency.
Mr Liu is the only person to have been arrested for organising the Charter 08 appeal, but others who signed it have reportedly being harassed.
In earlier interviews with the BBC, co-signatories of the petition said they were ready to be punished alongside Mr Liu, to stand up for their ideas.
Abolishing the law on inciting to subvert state power is among the reforms advocated in Charter 08.
The petition says the "practice of viewing words as crimes" should be stopped.