Soviet Union

League of Nations

Sep 18, 1934

Soviet Union admitted to League of Nations.

Red Army generals

Jun 11, 1937

Soviet leader Josef Stalin begins a purge of Red Army generals.

Agreement

Aug 23, 1939

Nazis and Soviet Union sign Non-Aggression Pact in Moscow, dividing control over Eastern Europe.

Russian-Finnish War

Aug 30, 1939

Soviet Union attacks Finland. Russian-Finnish war, which ended around 1940 with Finland ceding territory to the USSR.

Attack on Poland

Sep 17, 1939

Soviet Union retakes part of Poland that later becomes Western Ukraine and Western Belarus. Attacks occur near Vilnius and Bialystok. It was then divided between Germany and the USSR.

Romania

Jun 28, 1940

The Soviet Union forces Romania to cede the eastern province of Bessarabia and the northern half of Bukovina to the Soviet Ukraine.

Lithuania, Latvia and Estonia

Jul 23, 1940

The Soviet Union announces Lithuania, Latvia and Estonia as part of the USSR.

Soviet-Japanese non aggression pact

Apr 13, 1941

Soviet Union and Japan sign a non-aggression pact. Japan nor the USSR wanted a two-front war, and each saw the other front as primary and paramount.

German Invasion of Soviet Union

Jun 22, 1941

Germany attacks Soviet Union as Operation Barbarossa begins. By the end of the year, Germany occupies Belarus and most of Ukraine, surrounds Leningrad.

Soviet Union CounterAttack

Nov 23, 1942

Soviet troops counterattack, breaking through the Hungarian and Romanian lines northwest and southwest of Stalingrad and trapping the German Sixth Army in the city. Forbidden by Hitler to retreat or try to break out of the Soviet ring, the survivors of the Sixth Army surrender on January 30 and February 2, 1943.

German surrender at Stalingrad

Feb 2, 1943

Germans fail to take Stalingrad. A German army of over 250,000 men has been destroyed.

Kursk

Jul 5, 1943

The Germans launch a massive tank offensive near Kursk in the Soviet Union. The Soviets blunt the attack within a week and begin an offensive initiative of their own.

The Soviets Massive Offensive

Jun 22, 1944

The Soviets launch a massive offensive in eastern Byelorussia (Belarus), destroying the German Army Group Center and driving westward to the Vistula River across from Warsaw in central Poland by August 1.

Soviet Union and Allies

Feb 4, 1945

Soviet Union and the Allies reach understanding on postwar spheres of influence in Europe during the Yalta and Postdam summit conferences.

Attack on Berlin

Apr 16, 1945

Soviet troops begin their final attack on Berlin.

Germany Surrenders

May 9, 1945

Germany surrenders to the Soviets.

War against Japan

Aug 9, 1945

The Soviet Union declares war on Japan and invades Manchuria.