Hitler overseeing Wermacht troops marching into Poland, September 1939
The Polish Campaign (Also know as the German invasion of Poland) was a joint-invasion between Germany and Soviet Union of Poland between September 1 and October 6, 1939.
It is generally considered the beginning of World War II.
Prelude[]
Even before Adolf Hitler came to power, the Weimar Republic had always wanted to annex Poland, which had been German territory before it became independant after World War I.
Once Hitler came to power in 1933, he immedialty started rebuiding the army, navy, and airforce and started annexing territories and countries such as Austria. Even after the annexation of the Sudetenland and Czechislovakia, Hitler still planned on invading Poland.
Britain and France soon realized this and threatened that if Hitler invaded Poland, they would intervene, these threats were ignored and on September 1, 1939, Germany invaded Poland.
German and Soviet Invasion[]
A German Heinkel He 111 bombing Poland, September 1939.
On September 1, 1,500,000 Wermacht troops marched into Poland, completely catching the Polish by Suprise. Later that day, German Bombers would start bombing Polish cities.