The Bizone or Bizonia[1] 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 August 1948[2][3] the entity became the Trizone[4] (sometimes jokingly called Trizonesia[5]). Later, on 23 May 1949, the Trizone became the Federal Republic of Germany, commonly known as West Germany.