Timeline

1939

1.09 the start of German aggression
17.09 the start of Soviet aggression; Polish government evacuates to Romania; where it is interned.
27.09 Service for Poland's Victory is formed
30.09 Wladyslaw Raczkiewicz becomes President; and General Wladyslaw Sikorski become Prime Minister of the Polish Government in Exile
8.10 Poland’s western and northern territory is incorporated into the Reich
12.10 The General Government is formed
4.12 Issue of Order nr 1 detailing the formation of the Union of Armed Struggle is issued

1940

9/10.02 first mass deportation of Polish citizens into the depths of the USSR; the second happens in April; the third in June 1940 and the fourth in June 1941
27.04 Order to establish the Auschwitz camp in Oswiecim (first transports arrive in June 1940)
21.06 Polish Government in Exile moves to London
07-10 Battle of Britain is waged with participation of Polish pilots

1941

30.07 The Sikorski-Majski Pact is signed in London; and on August 14 the agreement to establish a Polish Army in the USSR.

1942

14.02 The Union of Armed Struggle is transformed into the Home Army
24.03 The evacuation of the Polish Army in the USSR to the Middle East begins (ends in August 1942)
22.07 Start of the mass deportation of Jews from the Warsaw Ghetto to death camps

1943

12.04 German authorities announce the discovery of mass graves with the remains of Polish Officers murdered at Katyn by the NKVD
19.04 Outbreak of the Warsaw Ghetto Uprising (fighting continues until mid-May)
25.04 USSR breaks diplomatic relations with the Polish government in exile
4.07 General Wladyslaw Sikorski dies in an airplane accident off the coast of Gibraltar; General Kazimierz Sosnkowski is appointed Commander in Chief; Stanislaw Mikolajczyk is appointed Prime Minister
12–14.10 Battle of Lenino

1944

1.02 Home Army units in Warsaw assassinate Franz Kutschere; Chief of the SS and Police in the Warsaw District
02-03 First battles waged in Wolyn and Vilnius Region by Home Army units as part of Operation Tempest
18.05 Units of the II Polish Corps capture the German fortified position at Monte Cassino
21.07 Communists establish the Polish Committee of National Liberation in Moscow; on July 22 they announce their manifesto
1.08 outbreak of the Warsaw Uprising (fighting ends on October 3)
14.09 Polish and Soviet forces occupy Warsaw’s eastern bank

1945

17.01 Polish and Soviet forces enter central Warsaw
19.01 General Leopold Okulicki disbands the Home Army
28.03 Leaders of the Polish Underground are arrested by the NKVD
17–21.06 Talks held in Moscow to establish the Provisional Government of National Unity
18–21.06 Trial of 16 held in Moscow against leaders of the Polish Underground
28.06 Provisional Government of National Unity formed
5.07 the United States and Great Britain cease to recognize the Polish government in exile in London and recognize the Provisional Government of National Unity