On dawn Sept 1, 1939, almost simultaneous attacks were launched on the Polish Army garrison at Westerplatte and the Polish Post Office inside the city of Danzig.

The first day a German ship in the harbor shelled the base for hours. On subsequent days they bombed from the skies. The Poles in Westerplatte held out for 7 days before surrendering.

The Polish Post Office workers defended their building for 15 hours, and were subsequently convicted as illegal combatants and executed by the German invaders.

September 1, 1939 - Attacks at Westerplatte and the Post Office signal the beginning invasion (of Poland) by Germany

September 7, 1939 - The Polish garrison at Westerplatte surrenders

September 17, 1939 - The Soviets invade Poland from the East (following secret agreement with Germany)

September 30, 1939 - Polish government-in-exile was established in Paris and Hitler issued Directive Number 5, the partition of Poland between Germany and the USSR.

And so the Second Polish Republic existed from 1918 to 1939.