It was November 1978, when posters started appearing on a brick wall in central Peking demanding political reform, that marked the birth of the "Democracy Wall" movement.
Within months, a young electrician from the zoo, Wei Jingsheng, had made his mark as an outspoken contributor: "We want no more gods and emperors, no more saviours of any kind," he wrote. "Democracy, freedom and happiness are the only goals of modernisation."
By March 1979 Mr Wei had been arrested, and later that year was sentenced in a closed court to 15 years for "counter-revolutionary" activities.
These days the brick wall is long demolished and the pavement is lined instead by a government "Science Popularisation" exhibition. Glass-fronted exhibition panels extol the achievements of Chinese women scientists - propaganda left over from Peking's biggest ever international event, the World Women's Conference in the autumn.
Peking's skyline and China's global status have been transformed by 16 years of economic reform. But some things have not changed. In the city's No 1 Intermediate People's Court this morning, a trial will open with Mr Wei, 46, now accused of trying to overthrow the government. Since March 1979 he has spent only six months out of jail, and today is likely to receive another long prison term. Nor, despite a court spokesman's promise that the trial would be "open", have any ordinary Chinese, foreign diplomats or journalists been given passes to attend.
Mr Wei's trial will again put the international spotlight on China's judicial system and the government's intolerance of criticism.
The name Wei does not stick in the memory of Westerners in the way Mandela and Sakharov once did, although he is often dubbed the country's "most famous" dissident. But he has been a constant thorn in the side of the Chinese government for almost two decades.
Mr Wei has an unlikely counter-revolutionary background. He came from a family of Mao loyalists in Anhui province, and was a Red Guard before going to work as an electrician in the Peking Zoo. When the political climate thawed in 1978, he edited a journal called Exploration, and quickly embraced the Democracy Wall movement.
As well as being an advocate of democracy, he bluntly rejected Deng Xiaoping's policy of economic modernisation without political reform. "The people must maintain vigilance against Deng Xiaoping's metamorphosis into an autocrat," Mr Wei wrote, prompting his immediate arrest and heavy sentence, much of it spent in solitary confinement.
It was not until September 1993 that Mr Wei left prison, released on parole by the government in the hope of winning the 2000 Olympics for Peking. He immediately renewed his call for democracy and insisted he would not escape abroad. His robust opinions showed no sign of having been weakened by his prison experience.
It was his decision to meet a senior US government human rights official, John Shattuck, which terminated his new-found freedom. Soon after, on 1 April 1994, Mr Wei was detained, and has not been seen since. Today he may well disappear again, for a very long time.