The Berlin Wall was constructed in 1961 to prevent East Germans from escaping to West Berlin. Over the following decades, various political leaders took actions that eventually led to its fall in 1989. Willy Brandt created Ostpolitik in the 1960s-70s to improve relations between East and West Germany. In 1987, Ronald Reagan challenged Mikhail Gorbachev to "tear down this wall". Mass protests in East Germany in 1989 forced Erich Honecker to resign. On November 9th, 1989, the Berlin Wall fell, opening the border for reunification of Germany.