Germany celebrates 25th year of the most dramatic mass protests, on Thursday, in the run-up to the Berlin Wall's fall with a reenactment of its iconic candlelight march.
The ceremony in the eastern city of Leipzig comes one month to the day before the reunified capital marks a quarter century since the communist authorities threw open the despised Cold War barrier.
In that momentous autumn of 1989, successive Mondays saw mounting demonstrations against the Stalinist state in eastern cities.
The peaceful protest in Leipzig of 70,000 people on October 9 met with stunned disbelief from the East German authorities and Soviet troops. It proved a turning point after months of unrest and sparked fears of a bloody crackdown on the order of Tiananmen Square in Beijing that June.
German President Joachim Gauck, who was himself a pro-democracy pastor in the communist East, calls the night of October 9, 1989 "decisive".
"It encouraged people in countless places in the GDR to stand up against the communist dictatorship and for freedom and human dignity," he said in a statement this week, using the acronym for the communist East.
"Only that made the fall of the Berlin Wall and then German unity possible."
The border opening on November 9 brought the long-demanded liberty to travel for Easterners and would usher in the end of the regime, and of Germany's reunification the following October.
For the anniversary of the pivotal rally against Erich Honecker's dictatorship, Gauck will host his counterparts from ex-Warsaw Pact countries Poland, the Czech Republic, Slovakia and Hungary.
Former US secretaries of state James Baker and German-born Henry Kissinger will also be on hand in Leipzig.
They will gather at the Gewandhaus concert hall to pay tribute to the demonstrators throughout the Eastern Bloc who, at great personal risk, took to the streets to demand their freedom.
- 'They were the heroes' -
Former Gewandhaus conductor Kurt Mazur, who used his international renown to intervene with the East German regime on behalf of the demonstrators to prevent violence, said this week that he was still humbled by their courage.
"The people there were the heroes," the 87-year-old told a regional daily. "They were afraid but they reacted in a way that was incredibly clever. I still have the strength of their chants in my ears."
In the afternoon, the leaders will gather at Saint Nicholas Church for prayers for peace, whose weekly occurrence at the same site 25 years ago led by firebrand pastor Christian Fuehrer helped touch off the popular movement.
Fuehrer died in June this year and will be honoured at the commemorations.
They will culminate in a restaging with the people of Leipzig of the dusk candlelight procession, images of which went around the world in 1989, signalling a new wind was blowing in East Germany.
Their chants of "No violence" and "We are the people" -- a direct rebuke to the leaders of the "people's republic" -- became a rallying cry for a beleaguered nation of 17 million ready for change.
The Protestant Church played a major role in the downfall of the communist regime, thanks to a politicised clergy and the permission it enjoyed to hold public meetings under the noses of the Stasi secret police largely without drawing suspicion.
With reunited Germany now led by two easterners, Chancellor Angela Merkel and Gauck, the country still sees unification as a work in progress, despite growing economic and social equality between its two halves.