Timeline of the 1939 invasion of Poland

The invasion of Poland was a joint offensive on the Republic of Poland by Nazi Germany, the Slovak Republic, the Free City of Danzig, and the Soviet Union, which marked the beginning of World War II. The invasion began on 1 September 1939, when German, Slovak, and Danzig forces entered Poland. The Soviets invaded Poland on 17 September. The campaign ended on 6 October with Germany and the Soviet Union dividing and annexing the whole of Poland under the terms of the German–Soviet Frontier Treaty. The aim of the invasions was to disestablish Poland as a sovereign country, with its citizens destined for extermination.

The following is a timeline of the invasion, which includes events preluding to the offensives, battles and attacks during the invasion, before ending with the last Polish armed forces surrendering on 6 October, which then begins the Polish resistance movement against the German Military Administration in Poland and the Soviet Union occupational administration.