Blitzkrieg's Opening Shots: The Invasion of Poland - 1st September 1939

23 March – Enabling Act passed by the Reichstag allows the establishment of a National Socialist dictatorship.

2 August – President Hindenburg dies. Hitler assumes both Chancellorship and Presidency.

16 March – Hitler announces the expansion of the German Army (Heer) to thirty-six divisions and 300,000 men. Conscription is reintroduced.

21 May – a new 'Armed Forces' Law establishes a separate German Air Force (Luftwaffe).

18 June – Anglo-German Naval Agreement permits the building of a modern German Navy (Kriegsmarine).

1 July – Truppenamt renamed the Army General Staff (Oberkommando des Heeres - OKH)

4 February – Blomberg and Fritsch resign. Hitler creates the Armed Forces High Command (Oberkommando der Wehrmacht – OKW) under Keitel.

29 September – France and the UK agree to German demands that Czechoslovakia cede the Sudetenland to them at the conference in Munich.

24 October – Ribbentrop demands the return of Danzig and special concessions in the Polish Corridor.

15 March – Wehrmacht invades and occupies the remainder of Czechoslovakia, eventually allowing Slovakia to form a puppet state.

31 March – Britain ends policy of appeasement with guarantees to Poland and Anglo-French support.

3 April – Plan Weiss issued by OKW, stating that the military build-up against Poland should be complete by 1 September.

28 April – Hitler abrogates Polish-German Non-Aggression Pact and Anglo-German Naval Agreement.

15 June – Operations order from OKH specifies mission and composition of ground forces to participate in Plan Weiss.

23 August – German Foreign Minister Joachim von Ribbentrop and Soviet Foreign Minister Vyacheslav Molotov sign the German-Soviet Non-Aggression Treaty (also known as the Nazi-Soviet Pact or the Molotov-Ribbentrop Pact).

25 August – Hitler orders the invasion to start at 04.00 the next day but cancels order once he learns of the British and French guarantees.

31 August – Hitler orders the attack on Poland to begin at 04.45 the next day.

1 September – The Wehrmacht crosses the frontier and attacks Polish air and naval bases.

3 September – UK and France declare war on Germany. Army Group North cuts the Polish Corridor while Army Group South crosses the Wartha.

5 September – Piotrkow falls and the way is open for an advance on Warsaw. Polish forces are ordered to retreat behind the Vistula.

7 September – German panzers reach the outskirts of Warsaw but are stalled due to heavy fighting. Marshal Rydz-Smigly decides to relocate his HQ from Warsaw to Brzesc-nad-Bugiem.

9 September – Army Poznan launches counterattack that catches the German 8th Army by surprise.

15 September – Army Group North reaches the outskirts of Warsaw, siege resumes.

19 September – Army Krakow attempts to breakout towards Romania via Tomaszow Lubelski.

3 October – Army Group South becomes OB East and responsible for Polish occupation. German 10th Army moves westwards. Three frontier army commands established.

6 October – Last major Polish ground unit under General Franciszek Kleeberg surrenders near Kock.

12 October – Hitler orders the establishment of the General Government in Poland.

18 October – Army Group South relieved as OB East and ordered to move westwards. Frontier Army Command Centre becomes OB East.

22 October – German 3rd Army (Frontier Army Command North) moves westward. Wehrkreis (Military District) I assumes control of Frontier Army Command North area.

26 October – Occupation turned over to civilian control. Dr Frank becomes Governor General and military forces are restricted to security duties.

The Campaign Begins

The opening shots of World War II were fired by the old German battleship Schleswig-Holstein, sitting in Danzig harbour, at the Polish garrison on Westerplatte at 04.00, 1 September 1939. Hitler had planned to start the campaign on 26 August, but the Anglo-French security agreement with Poland forced him to postpone the attack in an attempt to try additional diplomatic moves to further isolate the Poles. Not all units received the stand-down orders though and a few minor border incidents occurred, including one which saw a Brandenburger unit (effectively the Wehrmacht's Special Forces) try and capture a rail junction and tunnel in the key Jablonka Pass through the southern Carpathian Mountains. The Poles had mobilised around 700,000 men but had been pressured by the British and French not to declare full mobilisation (haunted by the spiralling events that led to World War I) despite the obvious preparations by their larger neighbour. Marshal Rydz-Smigly finally did so on 31 August.

Following Operation Himmler (where SS troops dressed in Polish uniforms staged a phoney attack on a radio station), fighting quickly erupted in the port of Danzig, which was conducted mainly by paramilitary forces. The remnants of the Polish fleet were sunk by air attack, including Poland's last two major surface combatants, the destroyer Wicher and the minelayer Gryf. Overall, the German attack came as a tactical surprise to the Poles, with many reservists being still en route to their units, and some units still moving to their deployment areas. The Polish forces in the Pomeranian Corridor, their political deployment (to stop the Germans seizing the corridor in a 'Sudetenland' style move) now defunct, began a fighting withdrawal against German 4th Army (under General der Artillerie Gunther von Kluge and part of Generaloberst Fedor von Bock's Army Group North). The Pomorska Cavalry Brigade fought a series of engagements over an entire day with the German 20th Motorised Infantry Division. In one action, the 18th Lancer Regiment caught a German infantry battalion in the open and decimated it, but was eventually forced to retreat by some armoured cars. Italian war correspondents saw the scene the next day and were told that those troopers who had been killed, had been killed while charging tanks. The story quickly gained a life of its own and was a staple of German propaganda and one of the most enduring myths of the Polish campaign.

While the German 4th Army crossed the Pomeranian Corridor, the German 3rd Army (under General der Artillerie Georg von Kuchler and also part of Army Group North) entered Poland from East Prussia and began its advance towards Warsaw. However, it quickly became entangled on the Mlawa fortification line, manned by the Polish 8th and 20th Infantry Divisions. In trying to outflank the line, one of the few cavalry-verses-cavalry actions of World War II occurred when the German 1st Cavalry Brigade skirmished with the Polish Mazowiecka Cavalry Brigade along the Ulatkowka River. Meanwhile, Army Group South (under Generaloberst Gerd von Rundstedt) aimed to breakthrough both Army Lodz (under General Juliusz Rómmel, a distant relative of Erwin Rommel) and Army Krakow (under Brigadier General Antoni Szylling), envelope the Polish forces guarding the western frontier and then head for Warsaw. Initially, resistance was light, but then the German 4th Panzer Division ran into the Wolynska Cavalry Brigade around Mokra. Despite repeated attacks and Stuka support, the cavalry held their ground, even repulsing one attack with the help of an armoured train. The German attacks suffered from poor coordination between tanks and infantry – a reflection of the difficulty of attempting new tactics and implementing a new doctrine. It was only after suffering a high attrition rate that the cavalry was forced to retreat. Further south, the Germans had greater success against Army Krakow, who faced the highest concentration of German divisions plus most of its mechanised forces – four panzer divisions and four light divisions – and who was in danger of being overwhelmed by sheer German numbers.

Army Group North continued to try and cross the Pomeranian Corridor for the next couple of days with much of the fighting centred on the Tuchola Forest. It eventually succeeded in isolating the Polish forces guarding the seacoast, including the Westerplatte Garrison and trapping forces in the eastern part of the corridor, while the Polish 27th Infantry Division managed to fight its way to Bydgoszcz. With the positions on the Mlawa defence line having been outflanked, both Army Pomorze (under General Wladislaw Bortnowski) and Army Modlin (under Brigadier General Emil Krukowicz-Przedrzymirski) began to withdraw to the main defences on the Vistula with the result that Polish resistance in the corridor collapsed. Army Group North then began to transfer units into East Prussia for the advance on Warsaw. In the meantime, one of the more curious operations during the campaign took place in a quiet sector of the front in East Prussia. The only Polish operation on German soil, the Podlaska Cavalry Brigade raided into German territory, had some skirmishes with border guards and a local Landwehr unit, and then retreated towards Milewa.

Breakthrough in Silesia

Since part of the German plan called for the encirclement of the Polish forces in Western Poland, Army Groups North and South were separated from one another by Pomerania. Army Poznan (Kutrzeba) was thus isolated there – its original mission was political, to prevent an uncontested German seizure of Pomerania. However, Kutrzeba knew very well that the main German thrusts would be around his position and so strongly requested that his formation be allowed to begin operations against the northern flank of Rundstedt’s Army Group South, i.e. the German 8th Army (Blaskowitz). Rydz-Smigly refused, arguing that it would lead to their premature elimination. Interestingly enough, Rundstedt had been worried about exactly the sort of attack being proposed by Kutrzeba. Originally, he had wanted to cover this flank with German cavalry units but was told by Hitler to use the SS-Leibstandarte instead. Worried over the SS units lack of experience, he assigned the 30th Infantry Division to the job, although it was stretched thin by the amount of ground it had to cover. Despite this, he continued to press on with the main attack to the northeast through Silesia. The Wolynska Cavalry Brigade continued to hold up the 4th Panzer Division during the 2nd September but the Polish 7th Infantry Division was forced to withdraw due to pressure from the 1st Panzer Division and two infantry divisions. It withdrew towards Czestochowa leaving one bridge intact over the Warta River. This was quickly exploited by the 1st Panzer Division (despite a large-scale air attack by the Polish Air Force), followed by the German 10th Army (von Reichenau) committing extra forces to the attack, including the 3rd Light Division. Any major success here could result in a major drive developing towards Warsaw as the terrain was mainly flat farmland and the German 10th Army contained a large proportion of the German mechanised force. Meanwhile, continued German pressure also obliged Army Krakow (Szylling) to start withdrawing, although the mountainous terrain aided the defence and allowed them to withdraw in good order, preventing the Germans from taking advantage of the gap between that and Army Karpaty (Fabrycy).

The speed of the German advanced surprised the Poles, who had guessed that the main attack would come from Silesia in the direction of Warsaw. Army Prusy (Dab-Biernacki), which by that point had three infantry divisions and a cavalry brigade, had been deployed as the main strategic reserve but had yet to fully concentrate due to the delays in Polish mobilisation and the impact the Luftwaffe was having on Polish lines of communication. The 4th and 1st Panzer Divisions reached the area of Piotrkow on the 5th September and engaged the Polish 19th Infantry Division. In addition, one of the few major contacts between Polish and German armour occurred, with the Polish 2nd Tank Battalion knocking out seventeen Panzers, two self-propelled guns and fourteen armoured cars, for the loss of only two tanks, but the Poles did not use their armour as a concentrated force and so their impact was negligible. Kutrzeba continued to ask for permission to launch a counter attack but was again denied. By this point, the gap between Armies Lodz and Krakow had been fully breached and Army Prusy could not contain the advancing German forces, who took Piotrkow and had opened the way to Kielce by pushing back Army Krakow's northern flank. Rydz-Smigley ordered that all four armies (Krakow, Lodz, Prusy and Poznan) withdraw eastwards to the Vistula. In the south, German forces had finally made it through the mountains. Despite a determined defence, the German 2nd Panzer and 3rd Mountain Divisions forced the Polish 10th Mechanised Brigade to retreat. The remaining Polish forces were ordered to retreat back across the Dunajec River to cover the southern approach to the old capital of Krakow.

By this point, both sides had started to reassess their plans. OKH had been reluctant to commit too many of its divisions eastwards in case the French decided to intervene and start offensive operations. With little evidence of activity from the French, German fears about such an attack were waning but had not completely dissipated. It was becoming obvious to the commanders in the field that the Poles were trying to avoid a decisive battle west of the Vistula River and that the plans for Case White should be modified to account for the fact that their forces were going to have to move much farther eastwards than originally planned in order to surround and destroy the Polish Army. Brauchitsch and OKH remained hesitant about such a commitment, still worried about the possibility that having done so, the French would start offensive operations and it could prove difficult to disengage and redeploy the necessary forces to counter them. Brauchitsch forbade Bock to move too far eastwards, only changing his mind on the 9 September when it had become blatantly obvious that the Poles were trying to avoid the German attempts at encirclement by withdrawing. However, from the Polish perspective things were grim. There seemed little prospect in containing the main German thrust out of Silesia, while in many places, the Germans were advancing faster than the Poles could withdraw, so being able to form a new defensive line on the Vistula was far from guaranteed. This remained Rydz-Smigley's main objective, and to wait for the anticipated counter-offensive, although this was based on a serious misreading of Allied intensions. Despite declaring war on Germany with the UK on 3 September, French strategy was essentially defensive (there was only a very limited offensive into the Saar which was halted when Poland surrendered) and the British Expeditionary Force (BEF) would not arrive on the continent for months. It is possible that the French missed a massive opportunity – German officers interviewed after the war believed that their forces in the west were too weak to have repulsed a full-scale assault and had they done so, the French could have ended World War II almost before it had begun.

By the 7 September, after deciding to form a new strategic reserve (Army Lublin), Rydz-Smigley was convinced that the Germans would surround Warsaw within a week and so moved his HQ to Brest-Litovsk, leaving a small staff to handle the transition. This would prove to be a serious mistake, as at the time, Brest-Litovsk was not able to handle communications with the field armies, leaving them in patchy contact with the high command during the establishment of the new defensive line on the Vistula. The 5th Panzer Division found an undefended gap in the line through the Holy Cross Mountains and began moving behind the main Polish defensive line from the northwest. On the other flank, the German 4th Light Division and 45th Infantry Division seized Tarnow after Army Malopolska withdrew from the Nida River defence line and a battle ensued as Army Krakow tried to escape the encirclement quickly developing. The four central Polish armies continued to withdraw but found that German mechanised forces were outpacing them. Most worryingly, the 1st and 4th Panzer Divisions had taken advantage of the rupture between Armies Lodz and Prusy and were racing towards Warsaw. Further north, things were quieter as the Wehrmacht was consolidating its forces after shifting them eastwards through the Pomeranian Corridor. Bock had been arguing with OKH about conducting offensive operations further east, which would undermine Polish attempts to form a defensive line on the Vistula. OKH was initially reluctant but eventually came round to the idea that Bock's forces should move east and then attack down the east bank of the Vistula.

The Bzura Counterattack

With the situation rapidly deteriorating, Rydz-Smigley eventually agreed to Gen. Tadeusz Kutrzeba's pleas to be allowed to counterattack into the flank of the German Eighth Army with Army Poznan. Although the attack should have been supported by either Army Lodz or Army Pomorze, both the shortage of time and communication problems (due to the relocation of the High Command) meant that this was impossible. Rundstedt continued to warn Blaskowitz about the threat but German intelligence mistakenly thought that the majority of Army Poznan had been redeployed towards Warsaw and the Vistula defence line, plus the German 24th and 30th Infantry Divisions were busy with their movement east and strung out on the march. Army Pozan launched its counterattack on the 9 September, with the 14th, 17th and 25th Infantry Divisions in the centre, along with the Podolska and Weilkopolska Cavalry Brigades on the flanks. Although the Poles had difficulty in retaking the town of Piotek, once they had down so, reserves were committed (including some armour) and the German defence finally collapsed. By the end of the 10 September, both German infantry divisions were in full retreat with Army Poznan having taken around 1,500 prisoners from the 30th Infantry Division alone. Despite the initial surprise, the German reaction was swift. Instead of trying to confront the Polish attack directly, Rundstedt was determined to turn the situation to the Germans' advantage and encircle the Polish concentration. The 1st and 4th Panzer Divisions, which were near Warsaw, were ordered to move westwards to stop Army Poznan from escaping into the Polish capital. Two days later, the Polish attack had bogged down and the High Command ordered Army Poznan to breakout to the southeast and escape to Romania. Realising that was almost impossible, Kutrzeba looked to breakout towards Warsaw via Sochaczew in conjunction with Army Pomorze, which was arriving in the area. In addition, the German 1st Mountain Division had climbed through the Carpathian Mountains, reaching Sambor on the 11 September and the outskirts of Lwow the next day. Unfortunately for the Poles, the Germans struck first with the 16th Panzer Corps and strong support from the Luftwaffe, encircling large elements of both Army Poznan and Pomorze. By the 16 September, Polish defences were crumbling and Kutrzeba ordered whichever units were still mobile, breakout and escape towards Warsaw via the Kampinos Forest. Elements of the 15th and 25th Infantry Divisions, along with the Podolska and Weilkopolska Cavalry Brigades managed to breakout, but by the 21 September both Army Poznan and Pomorze had been destroyed and over 120,000 prisoners of war had been captured.

Despite it being a defeat, the Bzura counterattack actually had a couple of short-term benefits for the Poles. Firstly, it gave Army Warsaw and Army Lublin extra time to prepare their defences and secondly, it disrupted the main German advance towards Warsaw, delaying it by about a week. After the war, German commanders claimed the outcome of the counterattack would have been much more in the balance had the it been conducted earlier. In addition, Polish commentators criticised the focus of the attack, which should have bee further east, giving the forces involved more time and space to retreat back towards Warsaw when the German riposte came. Communications and inter-army coordination were also problematic. The counterattack highlighted two shortcomings the Polish Army had when compared to the Wehrmacht. The first, was that it was far less mobile than the Wehrmacht on both the operational and tactical levels – the Germans were able to move units from far and wide to reinforce the area, as well as move units locally to maintain numerical superiority. Secondly, Polish communications were antiquated when compared to the Germans, plus the Polish High Command was relatively isolated and found it difficult to coordinate units once the action began.

The Siege of Warsaw

With Warsaw acting as a magnet to retreating and still mobilising Polish units, the Warsaw Defence Command under Gen. Walerian Czuma and the mayor, Stefan Starzynski, prepared for a prolonged defence, ordering the city's residents to keep calm and prepare defences on its outskirts. The German 4th Panzer Division entered the city via the Ochota suburbs on the 8 September and was engaged with point-blank artillery fire. They took some losses from 37mm antitank fire but fighting petered out the next day when the division was redeployed to counter the attack at Bzura. When the advance on Warsaw recommenced on 15 September, it was by Bock's Army Group North, as Rundstedt's Army Group South was still busy with the Bzura counterattack. Army Group North's vanguard unit was von Kuchler's Third Army. OKH's change of mind allowed Third Army to attack down both sides of the Vistula, contacting Warsaw's defences at the Praga suburbs. Still, the Germans were unable to place a cordon around the city until after the Bzura counterattack had been defeated and the last pockets of resistance mopped up, allowing the remnants of Army Poznan to make it back to Warsaw. The next wave of fighting took place in the northern suburbs, while the Germans encircled the city with thirteen divisions, a third of their force in Poland. After bringing up over 1,000 artillery pieces, the first major attempt to break into the city was on 23 September but failed due the preparedness of the defences. The next attempt, on 25 September, involved over 1,200 aircraft. The attack caused great clouds of dust and smoke, interfering with bombing accuracy. Indeed, on subsequent raids, the Luftwaffe dropped so many bombs on German infantry in the northwest suburbs as to cause a major row between the Heer and the Luftwaffe, at one point being so serious Hitler had to intervene personally. The next day saw German infantry take the three Tzarist forts (Mokotow, Dobrowski and Czerniakow) that guarded the southern approaches to the city. That evening, the commander of the Polish forces in Warsaw, Gen Juliusz Rommel, sent envoys to the German Eighth Army to discuss terms for surrender. The next day, hostilities formerly ended and 140,000 Polish troops surrendered. The Modlin Garrison held out until the 29 September when its 24,000 troops under Gen. Wiktor Thommee finally surrendered.

Soviet Intervention

The Soviets announced a general mobilisation on 11 September and on 17 September, informed the Polish Ambassador in Moscow that the Red Army would intervene in the conflict to protect Ukrainian and Byelorussian ethnic minorities in Eastern Poland. The Polish High Command, expecting the start of the French counter-offensive that same day, was suddenly faced with a huge problem – operations by the Red Army would put paid to any hope of a prolonged Polish defence east of the Vistula. Of course, Red Army operations were a natural consequence of the Molotov-Ribbentrop Pact but Stalin had delayed the start of them over uncertainty as to the reaction of the Western Allies, the speed of the German advance, military operations in the Far East and the time needed to mobilise the Red Army. Besides what was happening in Poland, Stalin had to contend with the undeclared war with Japan. This conflict culminated with the victory at Khalkin Gol and an armistice was signed with Japan on 15 September. Military intelligence correctly estimated that German forces were now east of the proposed demarcation line and so Stalin was forced to act sooner than anticipated.

The purges initiated by Stalin in 1937 and 1938 had effectively decapitated the Red Army, which found it difficult to operate on this sort of scale. The speed of the German advance had caught the Soviet High Command by surprise and they estimated they would need several weeks to fully mobilise, however, in order to move into Poland and grab the spoils of the treaty agreement, it would necessitate the commitment of many Red Army units that were still not ready as mobilisation was proving to be quite chaotic. Not only that, as it was close to an upcoming harvest, it was difficult to fully fill out the Red Army with additional trucks from the civilian sector, leading to a shortage of support vehicles. Indeed, while the Red Army Order of Battle might present what seems to be conventionally configured ground forces, many units, being only partially mobilised, were organised on a local basis and deployed haphazardly. The lack of opposition meant that the Red Army relied in their armoured and cavalry forces to sweep into Poland. As it happened, plans to intervene were already in place, due to the planning that took place around the possibility of intervening during the 1938 Munich Crisis. Soviet forces consisted of two fronts (Byelorussian under Komandarm Mikhail P. Kovalev and Ukrainian under Komandarm Simyon Timoshenko), controlling twenty-five rifle divisions, sixteen cavalry divisions and twelve tank brigades with just over 466,000 troops. Soviet armoured forces actually outnumbered both German and Polish combined, with 3,739 tanks and 380 armoured cars, while the Red Air Force had over 2,000 combat aircraft, sixty percent of which were fighters. Polish border defences were light anyway but had been stripped bare by the redeployment of forces westwards, meaning the ratio of forces was staggeringly one-sided.

Initially, there was confusion on the Polish side when news of the Soviet invasion first began to filter through. Hopes that they were coming to Poland's aid were soon dashed, when armed clashes were reported. The Polish High Command ordered that Polish units should only engage Soviet units either in self-defence or if they tried to interfere with their movement toward the Romanian bridgehead, but the order wasn't received everywhere – the commander of the Border Defence Corps (KOP) ordered his units to resist Soviet incursions (Brigadier General W. Orlik-Ruckemann) with fighting breaking out all along the frontier, with the heaviest fighting taking place in Galicia, where a number of regular Polish units were gravitating towards the Romanian border. Galicia was also one of the few areas where there was significant fighting between the Polish and Red Army Air Forces, mainly taking place on the first day of the Soviet invasion. Despite the small size of the Polish forces at the border, the Soviets lost almost 1,000 troops killed and another 2,383 wounded, along with 42 tanks with another 429 breaking down.

German forces on the ground had not been advised as to the date of the Soviet invasion and were caught unprepared. Some German units were already to the east of the proposed demarcation line, including Guderian's XIX Corps. OKH issued a directive outlining the maximum point to the east of the demarcation line that units could advance to on 17 September. Over the next few days, OKH gradually pulled units back to the line, with Hitler issuing an explicit order to stop combat operations east of the line on 20 September, with all units to have withdrawn to the line by the 21 September. On 22 September, a ceremony took place where the Germans handed over the Polish fortress at Brzesc to the Soviets. The Germans were represented by Gen. Heinz Guderian (CO, XIX Corps) and the Soviets were represented by Col. S. M. Krivoshein (CO, 29th Tank Brigade). Despite precautions there was some accidental clashes between German and Soviet forces but in the main, both sides respected the agreement. As a result of the Soviet invasion, Rydz-Smigly ordered all Polish forces to retreat into Romania if they could. The point of this was to try and preserve as much of the Polish Army as possible, with an aim to evacuate it to France to continue the struggle against Germany. However, only the major formations received the order and few were in any position to do something about it (Army Krakow tried to break through German lines on 18 September in order to reach the Romanian border but the attack ultimately failed), and the Soviet invasion effectively cut that route off.

One point of contact that was diplomatically sensitive was the city of Lwow, where the Polish forces (some six divisions) were surrounded, with Germans on one side and Soviets on the other. The local commander, Gen. Langner, decided to surrender to the Soviets rather than the Germans, this taking place on 22 September. Ostensibly, the men were free to go home and the officers were free to try and reach Romania, but the NKVD rounded them up before they had a chance to get away with ultimately tragic results (see below). Many units from the northern front tried to move through Tomaszow Lubelski but were rounded up by the Wehrmacht, the last being captured on 2 October near Nisko. Others formed into a force of around 16,000 strong under the command of Gen. Franciszek Kleeberg who tried to move westwards and reinforce the defence of Warsaw. He hadn't received word that Warsaw had fallen, and ran into the path of the German 13th Motorised Infantry Division, fighting a four-day battle after which they were forced to surrender on 6 October.

Aftermath

The Soviet invasion shortened the campaign by several weeks. The eastern part of Poland was less well-developed, had fewer roads and was more suited to fighting a defensive battle. As Rundstedt observed, German casualties in the second half of the campaign were higher than that in the first – if they would have had to face a prolonged defence in Eastern Poland, they would have been higher still. As it was, it was the Soviets who occupied Eastern Poland. The immediate consequence was to prevent a large portion of the Polish Army from retreating to Romania. By 2 October, the Soviets had captured 99,149 troops. Later records show that they eventually captured 452,536 personnel, but this included a large number of government officials, police, postal workers, teachers etc. in an effort to 'de-Polonise' the region. A large number of captured officers and officials (over 22,000) were murdered at three sites in Byelorussia in 1940 on the direct orders of Stalin (carried out by Lavrentiy Beria, Head of the NKVD), one of the sites (in the Katyn Forest) being discovered by the Germans in 1943. Although Stalin denied that the USSR had been responsible and blamed Nazi Germany for the atrocities, Premier Mikhail Gorbachev finally admitted that the USSR was responsible on 13 April 1990.

Polish casualties during the campaign amounted to 66,300 KIA, 133,700 wounded, 587,000 taken prisoner by the Germans and over 100,000 by the Soviets. The Germans suffered around 16,000 KIA and 32,000 wounded. The Germans had 674 tanks knocked out, with 217 being total write offs. Other equipment losses included 319 armoured cars, 195 artillery pieces, 6,046 vehicles and 5,538 motorcycles. For the Wehrmacht, Poland was an important learning experience in developing and fine tuning the tactics of Blitzkrieg, especially with the far more daunting mission of tackling France on the horizon. From our perspective in the 21st Century, it is difficult to tell how highly regarded the French Army was in 1939, being large, relatively well-equipped and victorious (admittedly with British help) in the First World War. It is only after their defeat in 1940, were the shortcomings laid bare for all to see. While the result of the Polish Campaign was never in serious doubt, given the disparities in military power between Germany and Poland, men and machines had to be tested, along with new organisational structures, training, technology and methods of integrating the different combat arms into a cohesive fighting force. It validated the use of the panzer division, the revolutionary methods of combined arms warfare and provided many units with their first experience of combat. Many observers dismissed the result as a reflection on the poor performance of the Polish Army but this underestimated the importance of the new tactics. The Germans, given the intensity of the later fighting, drew a different conclusion, one that underlined the importance of the new style of warfare.

While German Army performance had been very good, there were still aspects that needed to be improved. The light divisions had proven to be a failure, with neither the strength of the infantry divisions or the firepower of the panzer divisions. They were converted to be more like the latter in time for the French campaign. Certain aspects of the combined arms battle needed improvement too. The panzer divisions were armour heavy and infantry light, while tank-infantry coordination had been poor. Evaluation was made of certain equipment, for example, the MG34, while an accurate weapon, was found to have reliability problems under battlefield conditions, in particular where it was exposed to dust or mud. The acquisition of a replacement was accelerated and resulted in the MG42, a much more reliable weapon with a high rate of fire. Some infantry commanders complained about the awkward and heavy pack issued to the troops, recommending changes to allow greater freedom of action and comfort, plus a special grenade sack for the individual soldier. The development of a wide selection of artillery was proven to have been a wise move and the 88mm flak gun found to be especially effective in engaging bunkers and fortifications. The PzKpW I and II were found to be too light for use in Blitzkrieg and the decision was taken to increase the numbers of PzKpW III and IV in the panzer divisions, although the PzKpW II would be retained for a time, for reconnaissance operations. Eventually PzKpW I and II chassis were used as the basis of self-propelled and assault guns. In addition, the supply of spare parts and the system of maintenance for the panzer divisions needed to improved. The Luftwaffe had played an important part, gaining air superiority and then undertaking interdiction and close support but more attention was needed on the latter to improve ground-air coordination. The Red Army, while concentrating on its victory over Japan at the Battle of Khalkin Gol, learned some lessons but ignored many. One of the more serious weaknesses was the level of training of all ranks, especially in the senior officer corps and specialist troops. German officers who had had contact with the Red Army since the late 1920s were surprised how far the Red Army had deteriorated in that time – a factor in which would have been the decapitation of the Red Army during the purges on the late 1930s. Halder estimated that it could take up to a decade for the Red Army to return to the level of competence it exhibited in the early 1930s. One indication of this was the level of tank losses suffered – the Red Army lost around fifteen percent of its tanks against a relatively minor opponent due to it being ill-prepared to operate sophisticated equipment on the battlefield. The 'Winter War' with Finland would bring the Red Army's problems into the spotlight and suggested to the Germans that despite their shiny new toys, the Red Army was really a shadow of its former self, boosting Hitler's plans in the East.

Roughly 100,000 Polish troops made it out of Poland via Romania, Hungary and the Baltic Republics, 35,000 made their way to France where they served in four divisions and a mechanised brigade during the 1940 campaign in the West. After the French defeat, around 19,000 Poles made their way to the UK and North Africa where they formed the core of another Polish army. This included Colonel Stanislaw Maczek and much of the 10th Mechanised Brigade, formerly of Army Krakow. It formed the basis of the 1st Polish Armoured Division, fighting under British command during the Northwest Europe campaign of 1944-45. A second Polish corps was formed in North Africa, augmented by Soviet PoWs released by Stalin in 1942, which famously took Monte Cassino in 1944 and took part in the latter stages of the Italian campaign.

If the Polish Campaign revealed the technical expertise of the Wehrmacht, it also revealed something darker. While civilian casualties in war are often unavoidable, a broader German disregard for 'collateral damage' in this campaign was evident from the start, and German reprisals against the civilian population unusually harsh. The worst culprits seemed to be the German paramilitary groups and the new SS units. Some of their actions led a number of Wehrmacht commanders, such as Blaskowitz, to complain directly to Hitler. This hinted at far worse to come, with warfare in Eastern Europe degenerating into appalling savagery. For Poland, World War II was an unbridled tragedy with its thriving Jewish community being annihilated and the names of concentration camps such as Auschwitz, Belsen and Treblinka forever etched into the annuls of history as symbols of genocide. Even the Allied victory in May 1945 was little comfort to Poland as having been 'liberated' by the Soviet Union, it was then subject to over forty years of Communist rule. The Soviet Union kept the half of Poland it occupied, while Poland itself shifted west, absorbing German territory including East Prussia and displacing the populace.

Appendix 1: Red Army Order of Battle (17 September 1939)

3rd Army (Komkor Vasily I. Kuznetsov)
          4th Rifle Corps
                    27th Rifle Division
                    50th Rifle Division
          Lepel Group
                    5th Rifle Division
                    24th Cavalry Division
                    22nd Tank Brigade
                    25th Tank Brigade
11th Army (Komkor Nikifor Medvedev)
          16th Rifle Corps
                    2nd Rifle Division
                    100th Rifle Division
          3rd Cavalry Corps
                    7th Cavalry Division
                    36th Cavalry Division
                    6th Tank Brigade
          24th Rifle Corps (Reserve)
                    130th Rifle Division
                    145th Rifle Division
10th Army (Komkor I G Zakharin)
          11th Rifle Corps
                    6th Rifle Division
                    33rd Rifle Division
                    121st Rifle Division
          16th Rifle Corps
                    8th Rifle Division
                    52nd Rifle Division
                    55th Rifle Division
          3rd Rifle Corps (Reserve)
                    113th Rifle Division
                    133rd Rifle Division
Dzherzhinsk Cavalry Mechanised Group
          6th Cavalry Corps
                    4th Cavalry Division
                    6th Cavalry Division
                    11th Cavalry Division
          5th Rifle Corps
                    4th Rifle Division
                    13th Rifle Division
          15th Tank Corps
                    2nd Tank Brigade
                    20th Motorised Brigade
                    21st Tank Brigade
                    27th Tank Brigade
4th Army (Komdiv Vasily Chuikov)
          23rd Rifle Corps
                    93rd Rifle Division
                    109th Rifle Division
                    152nd Rifle Division
          29th Tank Brigade
          32nd Tank Brigade

5th Army (Komdiv Ivan Sovietnikov)
          8th Rifle Corps
                    14th Rifle Division
                    44th Rifle Division
                    81st Rifle Division
          15th Rifle Corps
                    45th Rifle Division
                    87th Rifle Division
          36th Tank Brigade
6th Army (Komkor Fillipp Golikov)
          2nd Cavalry Corps
                    3rd Cavalry Division
                    14th Cavalry Division
                    24th Tank Brigade
          17th Rifle Corps
                    96th Rifle Division
                    97th Rifle Division
          10th Tank Brigade
          38th Tank Brigade
12th Army (Komandarm Ivan Tyuleniev)
          13th Rifle Corps
                    72nd Rifle Division
                    99th Rifle Division
          4th Cavalry Corps
                    32nd Cavalry Division
                    34th Cavalry Division
          26th Tank Brigade
          5th Cavalry Corps
                    9th Cavalry Division
                    16th Cavalry Division
          23rd Tank Brigade
          25th Tank Corps
                    1st Motorised Brigade
                    4th Tank Brigade
                    5th Tank Brigade
          13th Independent Rifle Corps
                    72nd Rifle Division
                    124th Rifle Division
                    146th Rifle Division
Front Reserve
          36th Rifle Corps
                    7th Rifle Division
                    25th Rifle Division
                    131st Rifle Division

Bibliography and Further Reading

Abarinov, Vladimir. (1993) The Murderers of Katyn, New York: Hippocrene Books Inc.

Carr, C. (1989) 'Poland 1939' in Military History Quarterly, Autumn 1989, pp. 56 - 67.

Chodakiewicz, Marek J. (2003) Between Nazis and Soviets: A Case Study of Occupation Politics in Poland 1939 – 1947, Lanham, MD: Rowman & Littlefield.

Cienciala, Anna M. (2008) Katyn: A Crime without Punishment, London: Yale University Press.

Eshel, D. 'Blitzkrieg - The Polish Campaign 1939' in Defence Update, No. 98, pp. 27 - 38.

Hargreaves, Richard. (2008) Blitzkrieg Unleashed: The German Invasion of Poland 1939, Barnsley: Pen & Sword Military.

Hooton, E R. (1994) Phoenix Triumphant: The Rise and Rise of the Luftwaffe, London: Arms and Armour Press.

Kennedy, Major R M. (1956) The German Campaign in Poland (1939), Department of the Army Pamphlet No. 20-255, Washington DC, April 1956. Available at http://www.ibiblio.org/hyperwar/USA/DAP-Poland/index.html#contents as well as being reprinted by The Naval and Military Press in 2003 (9781843425014) and Pickle Partners Publishing as a Kindle ebook in 2013.

Lukas, R C. (2005) Forgotten Holocaust: The Poles under German Occupation 1939 - 1944, New York: Hippocrene Books (Revised Edition).

Orlowski, Lt Cdr P. (2003) Second World War - The Polish Campaign 1939, Defence Research Paper, Advanced Command and Staff Course No. 6, Sept 2002 - July 2003, Joint Command and Staff College, Watchfield.

Prazmowska, Anita J. (1995) Britain and Poland 1939 – 1943: The Betrayed Ally, Cambridge: Cambridge University Press.

Rossino, A B. (2003) Hitler Strikes Poland: Blitzkrieg, Ideology and Atrocity, Lawrence, KS: University Press of Kansas.

Sanford, George. (2005) Katyn and the Soviet Massacre of 1940: Truth, Justice and Memory, Abingdon: Routledge.

Sword, Keith. (Ed) (1989) The Soviet Takeover of the Polish Eastern Provinces 1939-41, London: University of London.

Tooze, A. (2006) 'Hitler's Gamble' in History Today, Volume 56, Number 11 (November 2006), pp. 22 - 28.

Williamson, David G. (2009) Poland Betrayed: The Nazi-Soviet Invasions of 1939, Barnsley: Pen & Sword Books.

Zaloga, Steven J. (2002) Poland 1939, Oxford: Osprey Publishing, Campaign Series No. 107.

How to cite this article: Antill, P (19 February 2022), Blitzkrieg's Opening Shots: The Invasion of Poland - 1st September 1939 – Part 2 , http://www.historyofwar.org/articles/campaign_poland_1939_2.html

Blitzkrieg's Opening Shots: The Invasion of Poland - 1st September 1939 – Part 2

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