On November 9, 2009, the twentieth anniversary of the fall of the Berlin Wall, a large “Celebration of Freedom” was held at Brandenburg Gate in Berlin. In addition to Berlin Mayor Klaus Wowereit and Chancellor Angela Merkel, a number of famous international leaders greeted the crowd of celebrants; they included Russian President Dimitri Medvedev, French President Nicolas Sarkozy, British Prime Minister Gordon Brown, and U.S. Secretary of State Hillary Clinton. A video message from U.S. President Barack Obama was also broadcast. The events culminating in the fall of the Wall were symbolically reenacted by the toppling of a row of dominoes set up along the former East-West border between the Reichstag and Potsdamer Platz. To honor Poland’s and Hungary’s role both before and during the political transformation of 1989/90, the first dominoes were pushed over by Lech Wałęsa, former Polish president and Solidarność (Solidarity) chairman, and Miklós Németh, former Hungarian prime minister.