17 September 1939
After a note acknowledging the end of the Second Polish Republic is read out to Polish Ambassador in Moscow Wacław Grzybowski the Red Army troops cross the Polish border.
17 September 1939
Commander-in-Chief Edward Rydz-Śmigły issues an order for the Polish troops not to resist Soviet forces.
18 September 1939
Germany and the USSR issue a joint communiqué on the restoration of “order and people” in Poland and the “transformation of the conditions of her existence.”
19 September 1939
In line with the decision of the CPSU CC’s Political Bureau, Kliment Voroshilov takes a decision to transfer all the prisoners of war to the NKVD and, to this end, set up rallying points at the westward Soviet railway stations.
19 September 1939
Lavrenty Beria establishes the Board for Prisoners of War and Internees within the NKVD. Eight prisoner of war camps subordinate to him are established, among them at Ostashkov, Yukhnov, Kozelsk, and Starobelsk.
28 September 1939
In Moscow, the Soviet-German Boundary and Friendship Treaty is signed along with other secret documents, correcting the borders of zones taken by the occupiers.
2 October 1939
CPSU CC’s Political Bureau takes a decision on separating and separate quartering of Polish officers, policemen, and representatives of uniformed services and high-ranking officials of the Second Polish Republic at “special camps.”
3 October 1939
CPSU CC’s Political Bureau authorizes the War Councils of the Ukrainian and Belarusian fronts to approve the death sentences passed for the counter-revolutionary activities of the civilians and Polish Army soldiers.
9 October 1939
Decision is taken on quartering the Polish officer corps at the camps at Kozelsk and Starobelsk, and the functionaries of the remaining uniformed services of the Second Polish Republic, including the policemen, prison servicemen, and military police, at Ostashkov.
24 October 1939 - 23 November 1939
In accordance with an agreement with the German authorities, some 40,000 prisoners of war coming from Central Poland are transferred to the German side.