Invasion of Poland | World War II

Invasion of Poland | World War II


The attack of Poland, also known as the September Campaign, the 1939 defensive war, and the Poland campaign, was a Nazi Germany and Soviet Union attack on the Republic of Poland that marked the start of World War II. The German attack commenced on 1 September 1939, one week after Germany and the Soviet Union signed the Molotov–Ribbentrop Accord and one day after the Soviet Union's Supreme Soviet authorized the pact. On 17 September, the Soviets invaded Poland.

As a result, the Polish defense strategy was rendered obsolete. Faced with a second front, the Polish leadership decided that defending the Romanian Bridgehead was no longer a viable option and ordered an emergency evacuation of all troops to neutral Romania. Following the loss of the Polish forces at the Battle of Kock on 6 October, German and Soviet forces took complete control of Poland. Though Poland never formally surrendered, the invasion's triumph signified the end of the Second Polish Republic. Germany annexed western Poland and the old Free City of Danzig on 8 October, after an initial period of military administration, and placed the remaining block of territory under the control of the newly constituted General Government.


The National Socialist German Workers' Party, led by Adolf Hitler, came to power in Germany on 30 January 1933. Despite the fact the Weimar Republic had long sought to annex Polish territories, Hitler's plan to invade and partition Poland, annexe Bohemia and Austria, and create satellite or puppet states economically subordinate to Germany was his idea, not a realization of Weimar plans to invade and partition Poland, annexe Austria and Bohemia, and create satellite or puppet states was his idea, not completion of Weimar plans to invade and partition Poland, annexe Bohemia and Austria, and build satellite As part of this long-term strategy, Hitler attempted to improve German public sentiment by pursuing a policy of rapprochement with Poland, which culminated in the German-Polish Non-Aggression Pact of 1934.

Previously, Hitler's foreign policy sought to sever connections between Poland and France and coerce Poland into joining the Anti-Comintern Pact, forging a united front against the Soviet Union. If Poland consented to conduct war against the Soviet Union, it would be handed territory in Ukraine and Belarus to the northeast. Still, the Poles' sacrifices were expected to make meant that their nation would become mainly dependent on Germany, operating as little more than a client state. Accordingly, it forced Czechoslovakia to yield the Český Těšín region by presenting an injunction to that effect on 30 September 1938, which Czechoslovakia accepted on 1 October.

This region, which had a Polish majority, had been a point of contention between Czechoslovakia and Poland following World War I. Poland's annexation of Slovak territory eventually served as the pretext for Slovakia's participation in the German invasion. By 1937, Germany had ratcheted up its demands for Danzig, proposing the construction of an extraterritorial highway, part of the Reichsautobahn system, to connect East Prussia with Germany proper via the Polish Corridor. Poland rejected the idea, fearing that if it agreed to these conditions, it would become increasingly subservient to German influence and, like the Czechs, lose its independence.

Polish leaders likewise disliked Hitler. However, the British were also concerned that Germany's growing dominance and assertiveness would jeopardize their balance-of-power policy. As a result, Poland forged a military alliance with the United Kingdom and France on 31 March 1939, thinking that if Germany challenged Poland's independence and territorial integrity, they would be defended with their help. However, British Prime Minister Neville Chamberlain and his Foreign Secretary, Lord Halifax, intended to agree with Hitler over Danzig and possibly the Polish Corridor.

Breakdown of Talks

Hitler had already ordered to prepare for a possible military solution to the Polish crisis in the Case White scenario. In May, while they were planning the invasion of Poland, Hitler made it evident to his generals that the attack would not be without resistance, as it had been in Czechoslovakia. Germany eliminated the chance of Soviet opposition to a campaign against Poland with the surprise validation of the Molotov–Ribbentrop Pact on 23 August. The outcome of secret Nazi-Soviet discussions held in Moscow.

The talks persuaded Hitler that the Western Allies were unlikely to launch the war on Germany. Even if they did, due to Poland's lack of territorial assurances, they would be willing to negotiate a favorable solution for Germany following its conquest of Poland. Accordingly, it stated that they were ready to begin negotiations but that a Polish official with the authority to sign an agreement would need to come to Berlin the next day and prepare a set of offers in the interim.

The British Cabinet was satisfied that negotiations had been settled. Still, they saw the requirement for an immediate arrival of a Polish representative with full signing powers as an unacceptable ultimatum, remembering how Emil Hácha had been forced to sign his country away under similar circumstances just months before. German Foreign Minister Joachim von Ribbentrop recited a 16-point German proposal to Ambassador Nevile Henderson on the night of August 30/31. However, Ribbentrop declined to give the envoy a copy of the plans for transmission to the Polish government, claiming that the needed Polish delegate had not arrived by midnight. On 31 August, when Polish Ambassador Lipski went to see Ribbentrop to express Poland's willingness to negotiate, he revealed that he did not have the unlimited capacity to sign, and Ribbentrop dismissed him.

The French, who presumably still hoped for a diplomatic settlement, pressed him to revoke the order, oblivious that the Germans were fully mobilised and concentrated on the Polish border. The Gleiwitz occurrence, a false flag attack on a radio station, was dramatic close the boundary city of Gleiwitz in Higher Silesia by German parts posing as Polish troops on the night of 31 August, as part of Operation Himmler. Hitler ordered hostilities against Poland to begin at 4:45 a.m. on 31 August.

Opposing Forces


The Heer (Army) had 3,472 tanks on hand, including 2,859 in the Field Army and 408 in the Replacement Army. Four light divisions were allotted 453 tanks, while another 225 tanks were assigned to unattached regiments and companies. The Germans, in particular, possessed seven Panzer divisions, each with 2,009 tanks and a new operational philosophy. It was proposed that these divisions work in tandem with other military components, punching holes in the enemy line and isolating specific units that would be encircled and annihilated. The Luftwaffe had 1,180 fighters, 290 Ju 87 Stuka dive bombers, 1,100 conventional bombers (mostly Heinkel He 111s and Dornier Do 17s), 550 transport and 350 reconnaissance planes. Germany had over 4,000 aircraft in total, the majority of which were new.


When compared to countries like the United Kingdom or Germany, the Second Polish Republic emerged as an independent republic in 1918, 123 years after the Partitions of Poland. It was a comparatively impoverished and primarily agricultural country. The Polish military possessed fewer armored troops than the Germans, and these units, which were distributed among the infantry, we're unable to fight the Germans effectively.

The experiences of the Polish-Soviet War impacted the Polish Army's organizational and operational philosophy. Regardless, Polish cavalry units were utilized as mobile mounted infantry, and they had some success against both German infantry and cavalry. A typical Polish infantry division had 16,492 soldiers. It was armed with 326 light and medium machine guns, 132 heavy machine guns, 92 anti-tank rifles, and several lights, medium, heavy, anti-tank, and anti-aircraft field artillery pieces. Unlike the average German infantry division, which had 1,009 automobiles and trucks and 4,842 horses, the intermediate Polish infantry division had 76 cars and trucks and 6,939 horses.

Due to a lack of numbers and the obsolescence of its fighter planes, the Polish Air Force was at a significant disadvantage against the German Luftwaffe. Opposing to German publicity, it was not destroyed on the ground; in reality, it was successfully dispersed before the fighting began. None of its combat planes was damaged based on the early days of the conflict. The Polish Air Force lacked modern fighters at a period of rapid aviation progress, owing to the rejection of numerous advanced projects, such as the PZL.38 Wilk, and a delay in introducing a wholly new modern Polish fighter, the PZL.50 Jastrzb.

A 'Bomber Brigade,' a 'Pursuit Brigade,' and aircraft assigned to the various ground armies made up the Polish Air Force. The Polish troops were older than their German equivalents; in late 1938, the Polish Air Force requested 300 advanced PZL.46 Sum light bombers, but none were delivered by 1 September due to a delay in mass manufacturing. When problems with the installation of the new PZL.50 Jastrzb fighters were discovered in the spring of 1939. It was decided to temporarily switch to the manufacturing of the PZL P 11.G Kobuz fighter.

Despite this, due to the onset of the war, none of the 90 aircraft of this sort ordered was delivered to the Army. The task force comprised two armored brigades, four independent tank battalions, and 30 TKS tankettes assigned to infantry divisions and cavalry brigades. The 7TP light tank was a regular tank of the Polish Army during the invasion in 1939.


German Plan

General Franz Halder, the chief of the general staff, prepared the September Campaign, led by General Walther von Brauchitsch, the upcoming campaign's commander in chief. The infantry, which was far from fully mechanised but was equipped with fast-moving artillery and logistic support, was to be backed up by Panzers and small numbers of truck-mounted infantry to aid rapid troop movement and concentrate on localized parts of the enemy front, eventually isolating, surrounding, and destroying enemy segments. The before the war "armored notion," called Blitzkrieg by an American journalist in 1939 and championed by some generals, counting Heinz Guderian, would have had striking armour holes in the enemy's front and extending deep into rear areas. Still, the fight in Poland would be conducted more traditionally.

Hitler wanted Poland conquered in six weeks, while German planners estimated it would take three months. With Fall Weiss' massive enveloping manoeuvre, they planned to exploit their lengthy border completely. From three directions, German forces were to attack Poland:  

  • Military Group South, directed by Colonel General Gerd von Rundstedt, was to launch a significant onslaught across the western Polish frontier, striking from German Silesia and the Moravian and Slovak borders. The 8th Army of General Johannes Blaskowitz intended to push eastward against Łódź. First, the 14th Army of General Wilhelm List intended to press on into Kraków and turn the Poles' Carpathian flank. Then, with Army Group South's armor in the center, General Walter von Reichenau's 10th Army was to deliver the final blow with a northeastward advance into the heart of Poland.
  • A second attack route emerged from northern Prussia. Colonel-General Fedor von Bock led Army Group North. It included General Georg von Küchler's 3rd Army, which was to advance southbound from East Prussia, and Army General Günther von Kluge's 4th Military, which was to attack eastward over the Polish Corridor's base.
  • A tertiary offensive by partnered Slovak units from Army Group South from Slovakia.
  • The German minority in Poland would help by assisting Volksdeutscher Selbstschutz forces in diversion and sabotage activities planned before the conflict.

The main Polish Army was to be trapped and annihilated west of the Vistula, and all three attacks were to converge on Warsaw. Thus, fall Weiss was the first operation of the Second World War in Europe, starting on 1 September 1939.

Polish Defense Plan

Poland's defense plan, "Plan West," was inspired by the country's intention to deploy forces immediately on the German-Polish border, motivated by the Polish-British Common Defense Pact. Many politicians believed that if Poland retreated from the disputed areas, Britain and France would sign a separate peace deal with Germany, similar to the 1938 Munich Agreement, allowing Germany to remain in those areas. Another source of Polish worry was that none of Poland's allies had expressly guaranteed Polish boundaries or territorial integrity. Thus, the West Plan permitted the Polish armies to retreat within the nation, but only slowly and behind planned lines, giving the armed forces time to complete their mobilization and launch a massive counteroffensive with the help of the Western Allies.

The Army was to withdrawal to the south-east of the nation if it failed to defend the majority of the state, where the rough territory, the Stryj and valleys, Dniestr Rivers, hills, and swamplands would provide natural lines of defense against the German advance, and the Romanian Bridgehead could be established. In addition, another third of the country's population was concentrated in the north-central region, between the large cities of Łódź and Warsaw. The difficulty of carrying out strategic manoeuvres was significantly increased by Polish forces' forward positioning, compounded by their lack of mobility. Polish units could not frequently retreat from defensive positions as more mobile German mechanised formations were overrunning them.

The British government pressured Marshal Edward Smigły-Rydz to evacuate the most modern elements of the Polish Navy from the Baltic Sea as the threat of war grew. In conflict, the Polish military leaders recognized that the Germans would most certainly sink the ships that remained in the Baltic. Accordingly, three warships of the Polish Navy carried out the Peking Plan. They were transported to the United Kingdom four days after the signing of the Polish-British Common Defense Pact.

Even though the Polish military was prepared for war, the civilian populace mainly was unprepared. As a result, the civilian populace was taken aback by Polish defeats during the German invasion. Due to a lack of groundwork for such a tragedy, the civilian population panicked and fled east, causing disorder, weakening soldier morale, and making traffic difficult for Polish troops. Furthermore, the agitprop had some adverse implications for the Polish forces, whose communications were further disrupted by inexplicable reports from Polish radio stations and newspapers, which often reported imaginary victories and other military operations, after being disrupted by German mobile units operating in the rear and civilians blocking roads.

German Invasion

One of the first acts of the war occurred on 1 September 1939, following multiple German-staged occurrences, such as the Gleiwitz incident, part of Operation Himmler, which German propaganda used as a pretext to claim that German soldiers were acting in self-defense. Despite some modest border victories, German technological, operational, and numerical superiority led the Polish Army to retire from the boundaries into Warsaw and Lwów. Many Polish Air Force units ran out of supplies, and 98 of them fled to Romania, which was neutral at the time. By 14 September, the Polish beginning strength of 400 had been reduced to 54, and air opposition had all but vanished, with the critical Polish air bases destroyed in the first 48 hours of the war.

On land, Germany attacked from three directions. First, the 35 divisions of Gerd von Rundstedt attacked southern Poland. Walther von Reichenau's armour was already across the Warta River by 3 September, as soon as von Kluge in the north had touched the Vistula River, some 10 kilometres from the German boundary, and Georg von Küchler was approaching the Narew River. Many German tanks were taken after a German onslaught broke the line, but the Polish defenders outflanked them. One of Reichenau's armoured corps had advanced 225 kilometers in the first week of the battle by 8 September and was now on the outskirts of Warsaw.

In the first week, Polish forces abandoned the provinces of Pomerelia, Greater Poland, and Polish Upper Silesia. Marshal Edward Rydz-Śmigły, the Polish commander-in-chief, ordered a mass retreat to the south-east, towards the Romanian Bridgehead, on 10 September. Meanwhile, the Germans tightened their grip on the Polish soldiers west of the Vistula and advanced deep into eastern Poland. Around the same time, advancing German forces arrived in Lwów, a significant city in the east of Poland, and on 24 September, 1,150 German planes struck Warsaw. The Polish defensive strategy called on an encirclement approach. On the other hand, Polish military strategists underestimated the speed of the German assault and anticipated Armia Prusy would need to be entirely mobilized by 16 September.

The Engagement of Bzura, which took place on the Bzura River west of Warsaw and lasted from 9 September to 19, was the greatest battle of the campaign. While retreating from the Polish Corridor's border area, the Polish troops of Pozna and Pomorze attacked the flank of the progressing German 8th Army, but the counterattack failed despite initial success. During the conflict, the Stukageschwaders alone dropped 388 t (428 short tons) of bombs.

Except for the isolated Warsaw, Poland west of the Vistula had been overrun by 12 September. In the early days of the combat, the Polish administration, commanded by President Ignacy Mościcki, and the high command, commanded by Marshal Edward Rydz-Śmigły, left Warsaw and travelled south-east, arriving in Lublin on 6 September. It then went to Kremenez on 9 September and Zaleshiki on 13 September, both on the Romanian border. Finally, Rydz-Śmigły ordered the Polish soldiers to retreat in the same way, behind the Vistula and San Rivers, to begin the defense of the Romanian Bridgehead sector.

Soviet Invasion

The German government had repeatedly asked Molotov whether the Soviet Union would maintain its end of the partition bargain from the start. The Soviet forces were standing firm along with their planned invasion points pending the conclusion of the five-month-long undeclared combat with Japan in the Far East, which occurred in the Battles of Khalkhin Gol, and the successful end of the struggle for the Soviet Union. On 17 September, once the Japanese threat of a "second front" was removed, Soviet Premier Joseph Stalin ordered his soldiers into Poland. In exchange for Lithuania's inclusion in the Soviet "zone of interest," the Soviets agreed to forgo their interest in the new boundary between Warsaw's lands.

The Polish defense had been breached by 17 September, and the only option was to retire and reassemble along the Romanian Bridgehead. The plans, however, were rendered obsolete almost immediately after the Soviet Red Army invaded Poland's eastern regions and established the Belarusian and Ukrainian fronts, in violation of the Riga Peace Treaty, the Soviet-Polish Non-Aggression Pact, and other bilateral and multilateral international treaties. Moreover, since the Polish government had abandoned the country and the Polish state had ceased to exist, Soviet diplomacy had lied that they were safeguarding the Ukrainian and Belarusian minority of eastern Poland.

The Korpus Ochrony Pogranicza, or Polish border defense forces in the east, comprised around 25 battalions. One of the fundamental reasons in persuading the Polish authorities that the war in Poland was lost was the Soviet invasion. Before the Soviet onslaught from the east, the Polish military's plan was for long-term defense against Germany in south-eastern Poland while waiting for relief from a Western Ally offensive on Germany's western frontier. The Polish administration, on the other hand, refused to surrender or negotiate peace with Germany.

Civilian Deaths

Hitler's first operation to create Lebensraum for Germans was the Polish Campaign. One of the motivations underlying German violence directed towards civilians was Nazi propaganda, which had worked tirelessly to persuade Germans that Jews and Slavs were Untermenschen. To scare the Polish people, disrupt communications, and undermine Polish morale, the German air force struck noncombatant targets and columns of refugees along the roadways from the first day of the invasion. During the bombing of Warsaw, the Luftwaffe killed 6,000 to 7,000 Polish citizens.

Atrocities were committed against Polish men, women, and children during the German invasion. SS and regular Wehrmacht units massacred tens of thousands of Polish citizens, including the Leibstandarte SS. Throughout the campaign, Adolf Hitler was known for torching villages and carrying out atrocities in several Polish towns, including massacres at Zoczew, Bonie, Bolesawiec, Goworowo, Torzeniec, Mawa, and Wocawek.

During Operation Tannenberg, a program of ethnic cleansing orchestrated by various factions of the German government, the Einsatzgruppen slaughtered tens of thousands of Polish citizens in 760 mass execution sites. The civilian casualties among the Polish populace totaled between 150,000 and 200,000 people. During the invasion, some 1,250 German citizens were also slain. Also, as members of ethnic German paramilitary organisations such as the Volksdeutscher Selbstschutz, which served as a fifth column during the invasion, 2,000 people died fighting Polish troops.


The German military districts in the territory of Posen, headed by general Alfred von Vollard-Bockelberg, and West Prussia, directed by General Walter Heitz, were established on September 8 and 13, 1939, respectively, in captured Greater Poland and Pomerelia. The German military ceded civil, administrative functions to Chiefs of Civil Administration under statutes passed on 21 May 1935 and 1 June 1938. Arthur Greiser was named CdZ of the Posen military district, and Danzig's Gauleiter Albert Forster was named CdZ of Hitler's West Prussian military community.

On 3 October 1939, Hitler established the military districts of "Lodz" and "Krakau" under major generals Gerd von Rundstedt and Wilhelm List, respectively, and Hitler designated Hans Frank and Arthur Seyß-Inquart as civil heads. As a result, the entire seized Polish territory was divided into four military districts. Frank was also named "supreme chief administrator" for the conquered territories at the same time. On 28 September, a secret German-Soviet protocol changed the August arrangements, transferring all of Lithuania to the Soviet sphere of influence; Foreign Secretary Edward Wood stated that they were only obligated to declare war on Germany because of the first clause Anglo-Polish Agreement in 1939.

On 23 May 1939, Hitler told his officers that the purpose of the invasion was not to take Danzig but to gain German Lebensraum. The details of this notion would be formulated later in the infamous Generalplan Ost. Nevertheless, the attack annihilated urban residential areas. Civilians became indistinguishable from combatants. The subsequent German occupation was one of the most ruthless incidents of World War II, ensuing in among 5.47 million and 5.67 million Polish deaths, including the mass murder of 3 million Polish citizens in extermination camps like Auschwitz, concentration camps, and several ad hoc massacres, where neutrals were rounded up, taken to a nearby forest, macerated, and executed.

Approximately 61,000 members of the Polish intelligentsia were killed in the Intelligenzaktion operations in 1939–1940, including scholars, former officers, clergy, and others, whom the Germans recognized as political targets in the Special Prosecution Book-Poland, accumulated before the conflict started in September 1939. Conferring to the Polish Institute of National Remembrance, amid 1939 and 1941, the Soviet occupation of Poland resulted in the deaths of 150,000 Polish citizens and the deportation of 320,000 others, when all those deemed dangerous to the Soviet regime were subjected to Sovietization, forced resettlement, imprisonment in labour camps, or murder, as the Polish officers in the Katyn massacre were. Since October 1939, those members of the Polish Army who were able to flee the Soviets or the Nazis have primarily sought refuge in British and French territory.

Eyewitness Accounts

From Lemberg to Bordeaux is a first-hand account of the conflicts that led to the collapse of Poland, the Low Countries, and France, written by Leo Leixner, a journalist and war correspondent. The book was first published by Franz Eher Nachfolger, the Nazi Party's major publishing firm. An American journalist and filmmaker, Julien Bryan, arrived in besieged Warsaw on 7 September 1939, under German bombing. He used one roll of color film (Kodachrome) and a lot of black-and-white films to photograph the beginning of the conflict.


There are a few common misconceptions about the Polish September Campaign.

Combat between the Polish Cavalry and German Tanks

Polish cavalry regiments did not engage German tanks with lances and swords. Approximately a third of the Uhlans were killed or injured despite their swift escape. Visiting the battlefield, a group of German and Italian war correspondents discovered the bodies of cavalrymen and horses among the armoured vehicles. Indro Montanelli, an Italian reporter, quickly published an article in Corriere Della Sera about the courageous Polish cavalrymen who rushed German tanks with sabres and lances.

Polish Air Force

In the initial days of the conflict, the Polish Air Force was not annihilated on the ground. Despite its numerical disadvantage, it had been redeployed from large air bases to small camouflaged airfields shortly before the conflict. On the ground, only a few trainers and ancillary planes were destroyed. Despite being outmanned and having fighters outmatched by more advanced German fighters, the Polish Air Force endured active until the second week of the operation, inflicting significant damage on the Luftwaffe. The Luftwaffe lost 285 planes due to operational reasons, with another 279 planes damaged, while the Poles lost 333 aircraft.

Polish Resistance to the Invasion

Another dispute is whether Poland caused significant casualties to the German Army and surrendered too soon. While exact figures differ, the Germans suffered roughly 45,000 deaths and lost 11,000 armed vehicles, counting 993 tanks and armored cars, 565 to 697 planes, and 370 artillery pieces. Even though the Anglo-French forces were far nearer to equality with the Germans in numerical asset and gear and were supported by the Maginot Line, the September Campaign continued about a week and a half less than the Combat of France in 1940. Furthermore, the Polish Army was developing the Romanian Bridgehead, which would have extended Polish defense, but the plan was thwarted when the Soviet Union invaded Poland on 17 September 1939. In addition, Poland never formally surrendered to the Germans. Under German occupation, forces such as the Armia Krajowa, Henryk Dobrzaski's guerillas, and the Leni continued to resist.

The First Use of Blitzkrieg Strategy

Blitzkrieg is frequently thought to have been Germany's first plan in Poland. Many early postwar histories, such as Barrie Pitt's The Second World War (BPC Publishing 1966), German credit victory to massive advances in military technology between 1918 and 1940, and claim that Germany, which put British interwar theories into practice, coined the term "Blitzkrieg" to describe the result. Some authors have criticized this notion.   

"Throughout the Polish Campaign, the use of motorized units revealed the assumption that they were intended merely to smooth the advance and support the infantry's activities," argues Matthew Cooper. As a result, any strategic application of the armored concept was dormant. The ultimate goal of that was not made the paralysis of command and the breakdown of morale. The traditional manoeuvers of rapid encirclement and the supporting activities of the Luftwaffe's flying artillery, both of which had as their goal the physical destruction of enemy troops, were only incidental by-products of the traditional German ground and air forces and were only accidental by-products of the ancestral German land and air forces, and were only incidental by-products of the conventional German ground and air forces, and were only related by-products of the traditional German setting and air Such was the Polish campaign's Vernichtungsgedanke (concept of destruction).

Last updated: 2022-January-09
Tags: History World War II
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