The Bizone or Bizonia was the combination of the American and the British occupation zones on 1 January 1947 during the occupation of Germany after World War II. With the addition of the French occupation zone on 1 June 1948 the entity became the Trizone (sometimes jokingly called Trizonesia). Later, on 23 May 1949, the Trizone became the Federal Republic of Germany, commonly known as West Germany.

The Americans and the British united their zones, creating the Bizone, in order to advance the development of a growing economy accompanied by a new political order in northwestern, western and southern Germany. The British zonal advisory board was restructured according to the example of the US zone Länderrat, so that the states in the British zone were empowered as autonomous legislating bodies, with the British military government confining itself to supervision.

No agreement with the Soviets was possible. Allowing the states in the Soviet zone to govern the central administrations, then still subject to the SVAG, would have meant the end of communist rule in the east. If the state parliaments and governments were not clearly dominated by communists, as had resulted from the last somewhat free elections in the Soviet zone in 1946, the Soviet Union would have had to waive the establishment of a communist dictatorship in the Soviet zone.

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