Sanation

After the coup of 12–14 May 1926 Piłsudski declined the presidency but remained the real leader of the state until his death in 1935. The camp's parliamentary base was the Nonpartisan Bloc for Cooperation with the Government. Its rule grew increasingly authoritarian: in 1930 opposition leaders were imprisoned in Brest, from 1934 an isolation camp operated at Bereza Kartuska, and the April Constitution of 1935 strengthened the presidency. After Piłsudski's death power was shared by President Ignacy Mościcki, Marshal Edward Rydz-Śmigły and Foreign Minister Józef Beck.

The defeat of September 1939 ended Sanation rule. General Sikorski's government-in-exile was made up largely of the camp's former opponents, who blamed it for the defeat and distrusted underground bodies linked to Piłsudski's followers, such as the Service for Poland's Victory. The quarrel between Sanation and its opponents weighed on Polish politics throughout the war.