High Quality Content by WIKIPEDIA articles! The Bizone, or Bizonia was the combination of the American and the British occupation zones in 1947 during the occupation of Germany after World War II. With the addition of the French occupation zone in March 1948, the entity became the Trizone (sometimes called jokingly Trizonesia, for example in a well-known Karneval song from that time). Later, on 24 May, the Trizone became the Federal Republic of Germany (commonly known as West Germany).