The Czechoslovak request was rejected by Poland and Czechoslovakia attacked the Polish part of the region on 23 January 1919 and forced Poland, which was at that time at war also with the West Ukrainian National Republic, to withdraw from the larger part of the area. After a ceasefire, both sides agreed to hold a plebiscite, which never took place, as the atmosphere in the region remained heated and turned violent. The entire area was divided by the decision of the Spa Conference from July 1920, thus in practice creating a Zaolzie area, leaving a sizable Polish minority on the Czech side and dividing the town of Cieszyn between the two states. The town Český Těšín was then the center of Český Těšín District, existing in the years 1920–1938 and 1945–1960.