achęta Gallery in Warsaw by painter and right-wing nationalist Eligiusz Niewiadomski.
The 1926 May Coup of Józef Piłsudski turned rule of the Second Polish Republic over to the Sanacja movement. By the 1930s Poland had become increasingly authoritarian; a number of 'undesirable' political parties, such as the Polish Communists, had been banned and following Piłsudski's death, the regime, unable to appoint a new leader, began to show its inherent internal weaknesses and unwillingness to cooperate in any way with other political parties.
World War II
The Sanacja movement controlled Poland until the start of World War II in 1939, when Nazi Germany's Invasion of Poland (1939) on 1 September and the Soviet invasion of Poland on 17 September, which followed the breaking of the Soviet–Polish Non-Aggression Pact, occurred. Warsaw capitulated on 28 September 1939. As agreed in the Molotov–Ribbentrop Pact, Poland was split into two zones, one occupied by Nazi Germany while the Kresy, or Borderlands, fell under the control of the Soviet Union. By 1941, the Soviets had moved hundreds of thousands of Poles into labor camps scattered across the Soviet Union, and the Soviet secret police, NKVD, had executed thousands of Polish prisoners of war.
Poland made the fourth-largest troop contribution to the Allied war effort, after the Soviets, the British and the Americans. Polish troops fought under the command of both the Polish Government in Exile in the theatre of war west of Germany and under Soviet leadership in the theatre of war east of Germany. The Polish expeditionary corps, which was controlled by the exiled pre-war government based in London, played an important role in the Italian and North African Campaigns. They are particularly well remembered for their conduct at the Battle of Monte Cassino, a conflict which culminated in the raising of a Polish flag over the ruins of the mountain-top abbey by the 12th Podolian Uhlans. The
