Katyn massacre

The Katyn massacre (Polish: zbrodnia katyńska, mord katyński, "Katyń crime"; Russian: Катынский расстрел Katynskij ra'sstrel, "Katyn shooting") was a series of mass executions of Polish nationals carried out by the People's Commissariat for Internal Affairs (NKVD), the Soviet secret police, in April and May 1940. Originally, the term "Katyn massacre", also known as the Katyn Forest massacre, referred to the massacre at Katyn Forest, which was discovered first and was the largest execution of this type.

The massacre was prompted by NKVD chief Lavrentiy Beria's proposal to execute all captive members of the Polish Officer Corps, dated 5 March 1940, approved by the Soviet Politburo, including its leader, Joseph Stalin. The number of victims is estimated at about 22,000. The victims were executed in the Katyn Forest in Russia, the Kalinin and Kharkiv prisons, and elsewhere. Of the total killed, about 8,000 were officers taken prisoner during the 1939 Soviet invasion of Poland, another 6,000 were police officers, and the rest were arrested Polish intelligentsia that the Soviets deemed to be "intelligence agents, gendarmes, landowners, saboteurs, factory owners, lawyers, officials and priests".