We're marking the 35th anniversary of one of the most seismic events of the 20th century: the fall of the Berlin Wall. We'll find out why it was built, how it fell, and how it brought an end to the Cold War. Joining Patrick Geoghegan is: Prof Patrick Major, Professor of Modern History at the University of Reading; Katja Hoyer, historian, author of ‘Beyond the Wall: East Germany, 1949-1990', and visiting Research Fellow at King’s College London; and Frederick Taylor, historian, author of ‘The Berlin Wall: A World Divided, 1961-1989' and a fellow of the Royal Historical Society of Great Britain.