The full story
Berlin remained the capital, but faced a series of threats from the far left and far right. In late 1918 politicians inspired by the Communist Revolution in Russia founded the Communist Party of Germany (Kommunistische Partei Deutschlands, KPD). In January 1919 it tried to seize power in the Spartacist revolt). The coup failed and at the end of the month right-wing Freikorps forces killed the Communist leaders Rosa Luxemburg and Karl Liebknecht. In March 1920 Wolfgang Kapp, founder of the right wing German Fatherland Party (Deutsche Vaterlands-Partei), tried to bring down the government. The Berlin garrison chose his side, and the government buildings were occupied (the government had already left Berlin). A general strike stopped the putsch being successful. In October 1, 1920: The Greater Berlin Act created "Greater Berlin" (Groß-Berlin) by incorporating several neighboring towns and villages like Charlottenburg, Köpenick or Spandau from the Province of Brandenburg into the city; Berlin's population doubled overnight from about 2 to nearly 4 million inhabitants.