The German offensive in the West began on September 1st and was later followed by the Soviet offensive in the East on September 17th.
German leader Adolf Hitler understood that his overall conquest of Europe relied on neutralizing Poland in the East, gaining a non-aggression assurance from the Soviets and preparing for battle against Britain and France in the West. From there, the final push would be against its one-time ally in the Soviet Union giving Hitler's Reich all of the slave manpower, agricultural resources and natural resources that it required.
The nation of Poland was a sovereign state before World War 1 (1914-1918) and ultimately cannibalized by German, Austrian and Russian power during the 1800s. It was only after the war, and the dismantling of the German, Austro-Hungarian and Ottoman empires that Poland was made whole once more. This time, it was given tracts of land from the fallen empires (including that of Tsarist Russia, which evolved - through an internal revolution - to become the Soviet Union in the 1920s. One of the key tracts allowed Poland access to the Baltic Sea in the north though this territory now divided Germany proper from its holdings in East Prussia. The Germans also lost the port city of Danzig which now lay under the control and protection of the League of Nations as a "free city" with no true national owner to be had.
To avoid another long and costly war, Britain and France - the major players in European politics at the time - sought the route of negotiation over war in an effort to contain the whims of Hitler, having already granted him Czechoslovakia. For Britain and France, there proved an understanding that, if Poland was attacked, both nations would commit militarily to the side of the Poles.
On the brink of war, Hitler's German forces numbered 60 divisions with 2,750 tanks, 2,315 aircraft and 9,000 artillery pieces against a Polish force of 39 divisions covering 880 tanks, 400 aircraft and 4,300 artillery systems. When the Soviet Union committed to the action, it brought with it 33 divisions numbering 4,736 tanks, 3,300 aircraft and 5,000 field guns of all types. Total manpower committed was 1.5 million German soldiers, 466,500 Red Army troops and 51,300 Slovakian soldiers against a smaller Polish threat.
At the end of the fighting, 66,000 Polish defenders would be killed with a further 133,700 to 200,000 wounded in action. To this was added the humiliation of 694,000 Polish soldiers taken as Prisoners of War (POW) to see certain death through starvation, abuse or execution across the many prison camps and death marches instituted after the invasion. In turn, the German Army managed losses of 16,300 with 30,300 wounded in the fighting while the Soviets fared better with 1,475 to 5,300 killed and 2,380 wounded in fewer weeks of fighting. Slovakian forces lost 37 with 114 wounded.
Adolph Hitler had already devised his plans apart from Britain and French involvement and these were finalized by his commanders on August 26th, 1939. A non-aggression pact had already been signed with the Soviets that same month and the final order to invade was given on August 31st, 1939. On September 1st, 1939, German forces crossed into Polish territory to officially begin World War 2.
Hitler's campaign was built upon technological superiority and excellent command in the first modern war. His offensives were executed under the "blitzkrieg" doctrine which involving skillful use of mechanized ground forces in concert with overwhelming air power to ensure a short campaign. Luftwaffe bombers neutralized key Polish infrastructure and fighters countered Polish fighters in turn. German armor negotiated roads and key choke points leading up to strategic Polish villages, towns and cities in their march to the capital city of Warsaw. Despite objections from Britain and France, Hitler continued his assaults and the promised military support for the Poles never came from its allies. The Poles did manage valiant defenses where possible though tactical movements by the Germans ensnared masses of Polish defenders in sweeping movements. Whatever elements were not caught in the German umbrella retreated eastwards towards the capital. On September 17th, the situation for Poland grew grim when the Soviet Union unleashed its army from the east.
Against insurmountable odds, the last Polish defenders surrendered on October 6th, ending the German-Soviet campaign against Poland. The government then existed only in exile.
The joint German-Soviet offensive ended with a near-perfect vertical division of Poland with the Soviet Union laying claim to the eastern and the Germans claiming the western half. East Prussia was now connected to German territory and the port of Danzig was under German control. The nation of Poland ceased to exist once more and this would remain as such until the end of the war in 1945. After this period, the country would fall under Soviet-influenced communist rule before seeing its independence once more in 1989 amidst the fall of the Soviet Empire. ©www.SecondWorldWarHistory.com
There are a total of (17) entries in the Timeline of the German Invasion of Poland (September 1st, 1939 - October 6th, 1939). Entries are listed below by earliest date to latest date.