The Wehrmacht gives Hitler a rousing welcome to Warsaw.
With the Polish army using WW1 tactics, cavalry attacks on advancing tanks, it was swept away within two weeks by a well organized modern German army, and Poland fell first victim to 'Blitzkrieg' (Lighting War).
On the 17th of September the Soviet Union invaded Poland, and the two invading armies met at Brest-Litovsk, the site of the Russian surrender to Germany in 1918. The Soviet Union's justification for the invasion of Poland were that these areas of Poland they had just invaded and occupied, were rightfully territories of the Soviet Union.
For three weeks Warsaw radio had defiantly played the Polish national anthem continuously over the air, and on the 21st of September Warsaw was attacked. On the 27th of September Poland surrendered, after which Warsaw was reduced to rubble.
Top Polish general at the surrender ceremony. All very formal and proper, but the Polish must be feeling the utter humiliation.
Polish generals with top Wehrmacht officers.
The despair is writ large on the faces of the Polish
German troops enter Warsaw as scattered groups of Polish civilians watch in dismay
France surrenders: June 1940: WW2