The late 1920s and early 1930s saw rising tensions mainly between three broad groups, the Communist Party of Germany (KPD) on one side, the Nazi Party on another, and a coalition of governing parties, mainly social democrats and liberals, on the other side.[6][7] Berlin in particular was the site of regular and often very violent clashes.[8] Both the Communists and the Nazis explicitly sought to overthrow the liberal democracy of the Weimar Republic, while the social democrats and liberals strongly defended the republic and its constitution.