The German reunification (German: Deutsche Wiedervereinigung) was the process in 1990 in which the German Democratic Republic (GDR/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. The end of the unification process is officially referred to as German unity (German: Deutsche Einheit), celebrated on October 3 (German Unity Day) (German: Tag der deutschen Einheit).

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