Fang Lizhi, one of China’s best-known dissidents whose speeches inspired student protesters in that country throughout the 1980s, died April 6 in Tucson. His wife, Li Shuxian, confirmed his death to the Associated Press, but the cause was not disclosed. He was 76.

Once China’s leading astrophysicist, Mr. Fang and his wife hid in the U.S. Embassy in Beijing for 13 months after the crackdown following the Tiananmen Square protests in 1989. In exile, he was a physics professor at the University of Arizona.

Mr. Fang inspired a generation, said his friend and fellow U.S.-based exiled dissident Wang Dan, who announced the death on Facebook and Twitter.

“I hope the Chinese people will never forget that there was once a thinker like Fang Lizhi. He inspired the ’89 generation and awoke in the people their yearning for human rights and democracy,” Wang wrote.

The son of a postal clerk in Hangzhou, Mr. Fang was admitted to Beijing University in 1952, at age 16, to study theoretical physics and nuclear physics. He became one of China’s pioneer researchers in laser theory.

He burst into political prominence during pro-democracy student demonstrations from 1986 to 1988, when he became China’s most outspoken and eloquent proponent of democratic reform. Chinese authorities said his speeches to students at the University of Science and Technology, where he was vice president, incited unrest.

Mr. Fang was expelled from the Communist Party and fired from his university post. But he refused to be silenced and received letters of support from across the country almost daily.

After the June 4, 1989, military crackdown on protesters in Tiananmen Square that crushed the pro-democracy movement, Mr. Fang and his wife fled to the U.S. Embassy. Mr. Fang and Li had both been named in Chinese warrants that could have carried death sentences if they had been convicted. U.S. diplomats refused to turn them over to Chinese authorities.

China’s decision to allow the couple to leave the country a year later eliminated a major obstacle to improving U.S.-China relations, which had deteriorated badly after the crackdown that left hundreds, and perhaps thousands of people, dead.

— Associated Press