Katyn massacre

April 1940 – May 31, 1940 · Katyn Forest

Mass execution by the Soviet NKVD of about 22,000 Polish officers, police and intellectuals held as prisoners; the USSR blamed Germany until it admitted the crime in 1990.

Key people

Joseph Stalin Approved the executions

Lavrentiy Beria Head of the NKVD, proposed the executions

Participants

Battles 1

World War II September 1, 1939 – September 2, 1945
- Invasion of Poland September 1 – October 6, 1939
- Battle of the Atlantic September 3, 1939 – May 8, 1945
- Operation Weserübung April 9 – June 10, 1940
- Battle of France May 10 – June 25, 1940
  - German invasion of the Netherlands May 10–15, 1940
  - Battle of Dunkirk May 26 – June 4, 1940
  - Dunkirk evacuation May 26 – June 4, 1940
  - Armistice of 22 June 1940 June 22, 1940
- Battle of Dunkirk May 26 – June 4, 1940
- Dunkirk evacuation May 26 – June 4, 1940
- North African campaign June 10, 1940 – May 16, 1943
  - Western Desert campaign June 11, 1940 – February 4, 1943
- Western Desert campaign June 11, 1940 – February 4, 1943
  - Operation Compass December 9, 1940 – February 9, 1941
  - Siege of Tobruk April 10 – November 27, 1941
  - First Battle of El Alamein July 1–27, 1942
  - Second Battle of El Alamein October 23 – November 11, 1942
- Battle of Britain July 10 – October 31, 1940
- The Blitz September 7, 1940 – May 21, 1941
- Operation Compass December 9, 1940 – February 9, 1941
- Invasion of Yugoslavia April 6–18, 1941
- Siege of Tobruk April 10 – November 27, 1941
- Battle of Crete May 20 – June 1, 1941
- Operation Barbarossa June 22, 1941 – January 7, 1942
  - Battle of Kiev (1941) 1941 – September 26, 1941
- Eastern Front (World War II) June 22, 1941 – January 21, 1955
  - Battle of Kiev (1941) 1941 – September 26, 1941
  - Second Battle of Kharkov May 12–29, 1942
  - Operation Uranus November 19–23, 1942
- Second Soviet-Finnish War June 25, 1941 – September 19, 1944
- Anglo-Soviet invasion of Iran August 25 – September 17, 1941
- Siege of Leningrad September 8, 1941 – January 27, 1944
- Battle of Moscow October 2, 1941 – January 7, 1942
- Attack on Pearl Harbor December 7, 1941
- Pacific War December 7, 1941 – September 2, 1945
  - Second Sino-Japanese War July 7, 1937 – September 2, 1945
  - Attack on Pearl Harbor December 7, 1941
  - Malayan campaign December 8, 1941 – January 31, 1942
  - Solomon Islands campaign January 1942 – August 21, 1945
  - Battle of Bataan January 7 – April 9, 1942
  - Battle of Singapore February 8–15, 1942
  - Battle of the Coral Sea May 4–8, 1942
  - Battle of Midway June 4–7, 1942
  - Kokoda Track campaign July 21 – November 16, 1942
  - Guadalcanal campaign August 7, 1942 – February 9, 1943
  - Battle of the Santa Cruz Islands October 25–27, 1942
  - Battle of Tarawa November 20–23, 1943
  - Operation Hailstone February 17–18, 1944
  - Battle of Saipan June 15 – July 9, 1944
  - Battle of the Philippine Sea June 19–20, 1944
  - Battle of Peleliu September 15 – November 27, 1944
  - Battle of Leyte October 17 – December 31, 1944
  - Battle of Leyte Gulf October 23–26, 1944
  - Battle of Luzon January 9 – August 15, 1945
  - Battle of Manila (1945) February 3 – March 3, 1945
  - Battle of Iwo Jima February 19 – March 26, 1945
  - Battle of Okinawa April 1 – June 22, 1945
  - Operation Ten-Go April 7, 1945
  - Soviet invasion of Manchuria August 9–20, 1945
- Burma campaign December 14, 1941 – September 13, 1945
  - Battle of Imphal March 8 – July 3, 1944
  - Battle of Kohima April 4 – June 22, 1944
  - Battle of Meiktila and Mandalay January 1 – March 29, 1945
- Solomon Islands campaign January 1942 – August 21, 1945
- Battle of Singapore February 8–15, 1942
- Battle of Midway June 4–7, 1942
- Lidice massacre June 10, 1942
- Battle of Stalingrad July 17, 1942 – February 2, 1943
  - Operation Uranus November 19–23, 1942
- Kokoda Track campaign July 21 – November 16, 1942
- Guadalcanal campaign August 7, 1942 – February 9, 1943
  - Battle of the Eastern Solomons August 24–25, 1942
  - Battle of the Santa Cruz Islands October 25–27, 1942
- Manhattan Project August 13, 1942 – January 1, 1947
  - Trinity nuclear test July 16, 1945
- Dieppe Raid August 19, 1942
- Battle of the Eastern Solomons August 24–25, 1942
- Operation Torch November 8–16, 1942
- Tunisian campaign November 17, 1942 – May 13, 1943
- Battle of Kursk July 5 – August 23, 1943
- Allied invasion of Sicily July 9 – August 17, 1943
- Italian campaign July 9, 1943 – May 2, 1945
  - Allied invasion of Sicily July 9 – August 17, 1943
  - Allied invasion of Italy September 3–16, 1943
  - Battle of Monte Cassino January 17 – May 18, 1944
  - Battle of Anzio January 22 – June 4, 1944
  - Operation Olive August 25 – December 31, 1944
  - Spring 1945 offensive in Italy April 6 – May 2, 1945
- Allied invasion of Italy September 3–16, 1943
- Battle of Tarawa November 20–23, 1943
- Tehran Conference November 28 – December 1, 1943
- Battle of Monte Cassino January 17 – May 18, 1944
- Battle of Anzio January 22 – June 4, 1944
- Operation Hailstone February 17–18, 1944
- Battle of Kohima April 4 – June 22, 1944
- Operation Overlord June 6 – August 30, 1944
  - Normandy landings June 6 – August 29, 1944
  - Liberation of Paris August 19–25, 1944
- Battle of Saipan June 15 – July 9, 1944
- Battle of the Philippine Sea June 19–20, 1944
- Operation Bagration June 22 – August 19, 1944
- Lvov–Sandomierz offensive July 13 – August 29, 1944
- 20 July plot July 20, 1944
- Warsaw Uprising August 1 – October 2, 1944
- Operation Dragoon August 15 – September 14, 1944
- Second Jassy–Kishinev offensive August 20–29, 1944
- Allied advance from Paris to the Rhine August 25, 1944 – March 7, 1945
  - Operation Market Garden September 17–25, 1944
  - Battle of the Bulge December 16, 1944 – January 25, 1945
- Lapland War September 15, 1944 – April 25, 1945
- Operation Market Garden September 17–25, 1944
- Battle of Metz September 27 – December 13, 1944
- Battle of Aachen October 2–21, 1944
- Battle of Debrecen October 6–29, 1944
- Battle of Leyte Gulf October 23–26, 1944
- Rescue of the Lost Battalion October 26–30, 1944
- Battle of the Bulge December 16, 1944 – January 25, 1945
- Siege of Budapest December 26, 1944 – February 13, 1945
- Vistula–Oder offensive January 12 – February 2, 1945
- East Prussian offensive January 13 – April 25, 1945
- Battle of Manila (1945) February 3 – March 3, 1945
- Yalta Conference February 4–11, 1945
- Battle of Iwo Jima February 19 – March 26, 1945
- East Pomeranian offensive February 24 – April 4, 1945
- Western Allied invasion of Germany March 22 – May 8, 1945
- Battle of Okinawa April 1 – June 22, 1945
  - Operation Ten-Go April 7, 1945
- Vienna offensive April 2–13, 1945
- Battle of Berlin April 16 – May 2, 1945
- Prague offensive May 6–11, 1945
- Potsdam Conference July 17 – August 2, 1945
- Atomic bombings of Hiroshima and Nagasaki August 6–9, 1945
- Surrender of Japan September 2, 1945