The Basic Treaty (German: Grundlagenvertrag) is the short-hand name for the Treaty concerning the basis of relations between the Federal Republic of Germany and the German Democratic Republic (German: Vertrag über die Grundlagen der Beziehungen zwischen der Bundesrepublik Deutschland und der Deutschen Demokratischen Republik). West Germany (FRG) and East Germany (GDR) recognized each other as sovereign states for the first time, an abandonment of West Germany's Hallstein Doctrine in favor of Ostpolitik.
After the entry into force of the Four-Power Agreement from 1971, both states began negotiations over a Basic Treaty. Like the Transit Agreement of 1972, the discussions were led by the Under-Secretaries of State Egon Bahr (for the FRG) and Michael Kohl (for the GDR). As part of the Ostpolitik of Federal Chancellor Willy Brandt, the treaty was signed on December 21, 1972 in East Berlin. It was ratified the next year in West Germany, despite opposition from hard-line conservatives. It came into effect in June 1973.
The signing of the treaty paved the way for both German nations to be recognised by the international community. Diplomatic relations were opened between the German Democratic Republic and:
