It was a picnic that changed the course of history.

Twenty years ago Wednesday, members of Hungary's budding opposition organized a picnic at the border with Austria to press for greater political freedom and promote friendship with their Western neighbors.

Some 600 East Germans got word of the event and turned up among the estimated 10,000 participants. They had a plan: to take advantage of an excursion across the border to escape to Austria.

Hungarian President Laszelo Solyom and German Chancellor Angela Merkel took part in festivities Wednesday marking the 20th anniversary of the "Pan-European Picnic," which helped precipitate the fall nearly three months later of the Berlin Wall.

"Hungarians gave wings to the East Germans' desire for freedom," Merkel told an audience that included politicians, diplomats, former East German refugees and several of the picnic's organizers.

One of the key factors allowing the Germans to escape: the decision by a Hungarian border guard commander not to stop them as they pushed through to freedom.

"It was an incredible experience for them," said the guard, Lt. Col. Arpad Bella, remembering the scene as the East Germans marched up the road to the border gates at Sopronpuszta and crossed into Austria.

"They embraced, they kissed, they cried and laughed in their joy. Some sat down right across the border, others had to be stopped by the Austrian guards because they kept running and didn't believe they were in Austria," said Bella, 63, during an interview where the gates once stood.

Bella said he and five of his men had been expecting a Hungarian delegation to cross by bus, visit a nearby Austrian town as a symbol of the new era of glasnost -- or openness -- under reformist Soviet leader Mikail Gorbachev, and return to Hungary.

Instead, at the planned time of 3 p.m., 150 East Germans approached the border gate, which had been closed since 1948.

"I had about 20 seconds to think about it until they got here," Bella said. "Had the five of us confronted the Germans, they would have (overwhelmed us)."

Once the initial group got through hundreds more East Germans joined them. Among the 600 were many young people and families with small children, Bella said.

Laszlo Nagy, one of the organizers of the picnic, said he was startled by the East Germans' actions, who left behind hundreds of cars and other possessions near the border for the chance to make the short walk to a new life in the West.

"Some of them were waiting for this moment for 20 or 30 years," Nagy said. "They left behind everything ... because freedom has the greatest value."

Dirk Mennenga was one of the "Ossies," a nickname for East Germans, who made it to Austria on that day. He had come to Hungary from Dresden.

"We had planned beforehand that we would try to cross the border through Hungary," Mennenga said. "We didn't know how easy or difficult it would be."

After seeing flyers promoting the picnic, Mennenga thought the event could provide an opportunity to escape West.

"It was a very emotional situation," Mennenga said. "There was a sole border guard. A young Hungarian man kept pointing the way and before we knew it we were in Austria."

While Bella was unaware of the East Germans' intentions, behind the scenes the Hungarian government had already decided that it would somehow let them go West.

Miklos Nemeth, Hungary's last prime minister of the communist era, said the picnic and the East Germans' breakthrough on that day was one in a series of steps that brought democracy to most of the Soviet bloc within a year.

"It was a planned process on behalf of the government, but it was a transition where everyone was also seeking to secure their own future," Nemeth said.

With 80,000 Soviet troops stationed in Hungary, Nemeth said it was difficult to know how Moscow would react to the unprecedented events.

"In my mind this was an important event, a test," Nemeth said. "And fortunately, Arpad Bella ... although he did not get any information, he decided in the right way."

Tens of thousands of East Germans had traveled to Hungary as expectations mounted that the more moderate Communist country might open its borders to the West.

They lived in makeshift shelters in Budapest on the grounds of the West German Embassy and at a tent city set up by a Catholic parish.

In the weeks after the picnic, East Germans continued to make attempts to cross the border, although many were still turned back. Then, on Sept. 11, Hungary began allowing all East Germans to travel West.

Bella continued his career as a border guard for several more years before retiring in 1996, later even working as a consultant on developing aspects of the Schengen agreement, which now allows for borderless travel within 25 European countries.

"I didn't think of myself as a hero. How could I? I wasn't even sure I'd be around for another week," Bella said. "If the Russians had wanted to come, they would have swept us aside like nothing."

At the commemoration, Merkel also met with Bella and other participants of the 1989 event. She described Bella as a "great man in history" and thanked him for his "contributions to freedom."

For Nagy, the significance of the events of Aug. 19 has grown over the past 20 years.

"At the time, we didn't feel like we were making history," Nagy said. "It was the world's greatest garden party."