At 18:53, in answer to a question by Riccardo Ehrman, an Italian journalist, Schabowski produced a piece of paper and announced that a decision had been made to allow East German citizens to emigrate from the German Democratic Republic. The atmosphere in the room was instantly electrified and questions came thick and fast. Unused to dealing with Western journalists, Schabowski became increasingly nervous and incoherent. A German journalist, Peter Brinkmann, called out repeatedly: "When does that come into force?" Schabowski scratched his head and stumbled over his reply as he looked at his documents. "As far as I know," he muttered, "that is immediately, without delay."

As the significance of what we were being told dawned on the millions of East German viewers watching at home, I finally got my hands on the only microphone and for the first time mentioned the Berlin Wall. At this point, the climax of the story, I prefer to hand over the narration to the Harvard historian Mary Elise Sarotte. Her new book The Collapse: The Accidental Opening of the Berlin Wall (Basic Books, £18.99) is by far the most thoroughly researched account so far of the events of November 9, 1989. She was not present at the time, but has spoken to or corresponded with all the key players who were. As one who was there, I can vouch for her objectivity and accuracy. Professor Sarotte writes:

Finally, Daniel Johnson, a foreign correspondent for Britain's Daily Telegraph, stood up and asked loudly: "What will happen with the Berlin Wall now?" The room suddenly became quiet as everyone waited expectantly for the answer, but only a long, fraught silence followed. It seemed as though Schabowski had suddenly lost the power of speech.

Finally the East German Politburo member ended the excruciating pause with the following words: "It has been drawn to my attention that it is 7:00 p.m. This is the last question, yes, please understand!" Then Schabowski suddenly tried to link the status of the Wall to the painfully slow process of disarmament, saying that the questions about the border "would definitely be positively influenced if the FRG and Nato would commit themselves to and carry out disarmament, just as the GDR and other socialist states have already completed certain preliminary steps."

With that confusing statement hanging in the air, and with Johnson and everyone else still waiting for a response to the question of what would happen to the Wall, Schabowski abruptly said: "Thank you very much!" and ended the press conference. It was 7:00:54 p.m. He had intentionally closed the press conference without determining the fate of the Wall. That task would, as a result, be left to the participants in the peaceful revolution later that night.