Bolesław Bierut ([bɔˈlɛswaf ˈbjɛrut]; 18 April 1892 – 12 March 1956) was a Polish Communist leader, NKVD agent, and a hard-line Stalinist who became President of Poland after the Soviet takeover of the country in the aftermath of World War II.
Bierut died under mysterious circumstances in Moscow on 12 March 1956 during a visit to the Soviet Union, shortly after attending the 20th Congress of the Communist Party of the Soviet Union during which Nikita Khrushchev delivered his "Secret Speech", denouncing Stalin's cult of personality. His death gave rise to speculation about poisoning or suicide.