In the forest near the village of Katyn, close to Smolensk, the NKVD shot about 4,400 Polish prisoners of war from the Kozelsk camp in the spring of 1940. It was part of a crime in which nearly 22,000 Polish citizens were murdered on the basis of the Politburo decision of 5 March 1940. The Germans revealed the graves on 13 April 1943; Moscow blamed the Germans and broke off relations with the Polish government, admitting the NKVD's guilt only on 13 April 1990.
1940
- 5 March 1940EventDecision to shoot Polish prisonersOn 5 March 1940 the Politburo adopted Beria's proposal to shoot 14,700 Polish POWs and 11,000 prisoners without trial. Stalin was among the signatories.
- 3 April 1940EventThe Katyn massacreOn 3 April 1940 the first prisoners left Kozelsk for their deaths. By mid-May the NKVD had killed almost 22,000 Polish officers, policemen and prisoners.
1943
- 16 March 1943EventThe discovery of the Katyn gravesIn March 1943 the German Secret Field Police examined mass graves of Polish officers in the Katyn Forest. The world learned of them only in April.
- 13 April 1943EventThe Germans announce the Katyn massacreOn 13 April 1943 Berlin radio announced the discovery of Polish officers’ graves near Smolensk. The dispute let Stalin break with the Polish government.
- 25 April 1943EventUSSR breaks relations with the Polish governmentOn the night of 25-26 April 1943 Molotov read Ambassador Romer a note breaking relations with the Polish government. The pretext was an appeal to the Red Cross.
- 25 September 1943EventThe liberation of SmolenskOn 25 September 1943 the Western Front drove the Germans from ruined Smolensk. Nearby Katyn also fell to the Soviets, and the NKVD began covering its tracks.