Friends of Liu Xia report she has landed in Germany after years of house arrest. Her husband, Nobel Prize winner Liu Xiaobo, died in detention last July.
Liu Xia was never charged with a crime but has spent eight years under house arrest.
Liu landed in Berlin from Beijing on Tuesday, where her arrival was greated warmly by rights groups.
"Sister has already left Beijing for Europe at noon to start her new life. Thanks to everyone who has helped and cared for her these few years. I hope from now on her life is peaceful and happy," her brother Liu Hui wrote on social media.
German Foreign Minister Heiko Maas confirmed her arrival on Twitter, praising the "good news that Liu Xia has arrived in Germany. Good, that a humane solution could be found. Liu Xia can now receive medical treatment in Germany. We hope for a speedy recovery."
Campaigners have called for Liu Xia's release ever since the 57-year-old poet and artist was put under house arrest in 2010, days after her imprisoned husband, Liu Xiaobo, was awarded the Nobel Peace Prize.
He had been sentenced to 11 years in prison on charges of inciting subversion of state power.
Liu Xiaobo died of liver cancer last July aged 61. He was a writer, critic and activist who called for political reforms and an end to one-party rule in China.
Chinese Premier Li Keqiang made a state visit to Germany on Monday and met with Chancellor Angela Merkel.
Berlin has been pushing China to let Liu leave the country following the death of her husband. In May, Germany said it would welcome the widow after a recording was released of her crying in desperation and indicating she was losing hope of leaving China.
Samantha Power, who served as the United States Ambassador to the United Nations under former President Barack Obama, praised Chancellor Angela Merkel's efforts in securing Liu's release, tweeting:"Finally. Thanks to Angela Merkel & the EU for pushing for her release."
Renowned Chinese Artist and dissident Ai Weiwei also praised the work of Germany and its chancellor in seeking Liu's release. "Germany has been constant for a long time, in negotiating with the Chinese government about Chinese political prisoners. And Liu Xia's release is a positive sign for this kind of international effort," he told DW.
Friends of Liu Xia had expressed concern for her mental health ahead of the first anniversary of her husband's death on Friday.
China has maintained that Liu Xia was free and accorded all rights guaranteed to her by law.
Western diplomats, however, disagree. They say Chinese authorities kept a close watch on her after the death of her husband and she was only allowed to meet and speak to friends and family in pre-arranged phone calls and visits.
ap,es/msh (dpa, AP, AFP, Reuters)