The territory of today's Slovakia was a part of Czechoslovakia from 1918 to 1938 and again from 1945 until 1989. Czechoslovakia was one of the states which came into existence after the breakup of Austria-Hungary at end of World War I in 1918. Czechoslovakia split up in 1939, when Slovakia, under Hitler's influence and pressure, declared independence and became an independent state. The state existed during World War II. It was a one-party totalitarian state which was a puppet ally of Nazi Germany. Under the regime, the state fought in the war on the side of Nazi Germany and deported about 70,000 of its Jewish citizens to Nazi extermination camps as part of the Holocaust.