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 on the first of June 1948 the entity became the Trizone (sometimes jokingly called Trizonesia, as, for example, in a well-known Karneval song from that time, the Trizonesien-Song). Later, on 23 May 1949, the Trizone became the Federal Republic of Germany, commonly known as West Germany.