Both German States Join the United Nations
Also called: Admission of the two German states to the UN
Following the Basic Treaty, East and West Germany became the 133rd and 134th members of the United Nations on the same day. The two Koreas joined together in the same way in 1991.

Bundesarchiv, Bild 183-M0925-306 / Hans-Joachim Spremberg · CC BY-SA 3.0 de · Source
After the Basic Treaty came into force, the UN General Assembly admitted the German Democratic Republic and the Federal Republic of Germany together on 18 September 1973, East Germany as the 133rd member and West Germany as the 134th.
Each now acted as a state in the international community, and around this time East Germany established relations with many Western countries. The simultaneous admission of a divided nation was repeated when North and South Korea joined the UN together in September 1991.