Northern Eurasia 1939: Molotov–Ribbentrop Pact
On 23 August 1939, even while it was fighting Japan on the Mongolian border, the Soviet Union shocked the world by agreeing to the Molotov–Ribbentrop Pact with Nazi Germany. Formally, this was a non-aggression pact between two ideological enemies. However a secret clause agreed to the division of eastern Europe. When the Germans invaded Poland in September, the Soviets joined in and invaded from the east.
23 Aug 1939 Molotov–Ribbentrop Pact▲
In August 1939 German foreign minister Joachim von Ribbentrop and Vyacheslav Molotov, his Soviet counterpart, signed the Treaty of Non-aggression between Germany and the Union of Soviet Socialist Republics in Moscow. The pact provided a guarantee that neither of the two powers would take up arms against the other, as well as secretly dividing eastern Europe between them.
1 Sep 1939 Germany invasion of Poland▲
Using several German-staged incidents as casus belli, Nazi Germany struck Wieluń, Poland, with the Luftwaffe at 04:40 on 1 September 1939—the first blow of World War II. Five minutes later, the German battleship Schleswig-Holstein opened fire on a Polish military transit depot in the Free City of Danzig, with Germany launching an all out attack on Poland’s northern, western, and southern borders later that day.
3 Sep 1939 Declaration of War on Germany▲
Responding to the German invasion of Poland, France and the United Kingdom declared war on Germany. The official Declaration of war by France and the United Kingdom was read out by the British Prime Minister Neville Chamberlain, in Westminster, London, on behalf of both countries. Although the declaration fulfilled the two powers’ guarantees to Poland, moves of practical support were limited.
17 Sep–6 Oct 1939 Soviet Invasion of Poland▲
In accordance with the Molotov-Ribbentrop Pact, the Soviet Union invaded Poland on 17 September, meeting the Germans invading from the west on 6 October. On 1 November, the Soviets annexed Eastern Poland, incorporating its territory into the Belarusian and Ukrainian Soviet Socialist Republics.
29 Sep–10 Oct 1939 Soviet influence over Baltic states▲
Following the fall of Poland in 1939, the Soviet Union pressured Finland and the Baltic states—Estonia, Latvia, and Lithuania—to conclude mutual assistance treaties. Pressure was applied to Estonia first, which also had to agree to host Soviet army, air, and naval bases in late September. Latvia and Lithuania followed in early October, although the Soviets agreed to reward the Lithuanians for their support by ceding the historically-disputed city of Vilnius to Lithuania from what had been Poland.