Question: when did east germany and west germany unite
Answer: The German reunification ( German : Deutsche Wiedervereinigung ) was the process in 1990 in which the German Democratic Republic ( GDR / DDR / East Germany ) joined the Federal Republic of Germany ( FRG / West Germany ) to form the reunited nation of Germany , and when Berlin reunited into a single city , as provided by its then Grundgesetz constitution Article 23 .