Fall Weiss (The German Invasion of Poland)
The German assault began at 04:00 on 26 August, preceded by German sabotage groups the night before that attacked the Jablunkov Pass and Mosty railway station in Silesia as well as planted a bomb at the railway station in Tarnów which killed 21 passengers, leaving 35 wounded.
Germany’s initial invasion force found a partially mobilized Polish army before them, many units still forming or moving to their designated frontline positions. Meanwhile, the Polish Navy sent its destroyer flotilla to Britain, executing Operation Peking.
Germany had a substantial numerical advantage over Poland and had developed a significant military prior to the conflict. The Heer (army) had some 2,400 tanks organized into six panzer divisions, utilizing a new operational doctrine. It held that these divisions should act in coordination with other elements of the military, punching holes in the enemy line and isolating selected units, which would be encircled and destroyed. This would be followed up by less-mobile mechanized infantry and foot soldiers. The Luftwaffe provided both tactical and strategic air power, particularly dive bombers that disrupted lines of supply and communications. Together, the so-called “new” methods, were nicknamed “Blitzkrieg.”
Aircraft played a major role in the campaign. Bombers also attacked cities, causing huge losses amongst the civilian population through terror bombing. The Luftwaffe forces consisted of 1,180 fighter aircraft, 290 Ju 87 Stuka dive bombers, 1,100 conventional bombers (mainly He 111s and Dornier Do 17s), and an assortment of 550 transport and 350 reconnaissance aircraft. In total, Germany had close to 4,000 aircraft, most of them modern. A force of 2,315 aircraft was assigned to Weiss. Due to its prior participation in the Spanish Civil War, the Luftwaffe was probably the most experienced, best trained and best equipped air force in the world in 1939.
Between 1936 and 1939, Poland invested heavily in the Central Industrial Region. Preparations for a defensive war with Germany were ongoing for many years, but most plans assumed fighting would not begin before 1942. To raise funds for industrial development, Poland sold much of the modern equipment it produced. In 1936, a National Defense Fund was set up to collect funds necessary for strengthening the Polish Armed forces. The Polish Army had approximately a million soldiers, but less than half of them were mobilized by 26 August. Latecomers sustained significant casualties when public transport became targets of the Luftwaffe. The Polish military had fewer armored forces than the Germans, and these units, dispersed within the infantry, were unable to effectively engage the enemy.
Experiences in the Polish-Soviet War shaped Polish Army organizational and operational doctrine. Unlike the trench warfare of the First World War, the Polish-Soviet War was a conflict in which the cavalry’s mobility played a decisive role. Poland acknowledged the benefits of mobility but was unable to invest heavily in many of the expensive, unproven inventions since then. In spite of this, Polish cavalry brigades were used as a mobile mounted infantry and had some successes against both German infantry and cavalry.
The Polish Air Force was at a severe disadvantage against the German Luftwaffe, although it was not destroyed on the ground early on, as is commonly believed. The Polish Air Force lacked modern fighter aircraft, but its pilots were among the world’s best trained.
Overall, the Germans enjoyed numerical and qualitative aircraft superiority. Poland had only about 600 aircraft of which only 37 36 P-37 Łoś bombers were modern and comparable to its German counterparts. The Polish Air Force had roughly 185 PZL P.11 and some 95 PZL P.7 fighters, 175 PZL.23 Karaś B, 35 Karaś A, and by late August, over 100 PZL.37 Łoś were produced. However, for the Campaign, only some 50% of those aircraft were mobilized. Only 36 PZL.37 Łoś bombers were deployed. All those aircraft were of indigenous Polish design, with the bombers being more modern than fighters, according to the Ludomił Rayski air force expansion plan, which relied on a strong bomber force. The Polish fighters were a generation older than their German counterparts. The Polish PZL P.11 fighter, produced in the early 1930s, was capable of only 365 km/h (approximately 220 mi/h), far less than German bombers; to compensate, the pilots relied on its maneuverability and high diving speed.
The tank force consisted of two armored brigades, four independent tank battalions and some 30 companies of TKS tankettes attached to infantry divisions and cavalry brigades. A standard tank of the Polish Army during the Polish Defensive War of 1939 was 7TP light tank. It was the first tank in the world with diesel engine and 360-degree Gundlach periscope. 7TP was significantly better armed than its most common opponents, the German Panzer I and Panzer II but only 140 tanks were produced between 1935 and the outbreak of the war. Poland had also a few relatively modern imported designs, such as 50 Renault R35 tanks and 38 Vickers E tanks.
The Polish Navy was a small fleet of destroyers, submarines and smaller support vessels. Most Polish surface units followed Operation Peking, leaving Polish ports on 20 August and escaping by way of the North Sea to join with the British Royal Navy. Submarine forces participated in Operation Worek, with the goal of engaging and damaging German shipping in the Baltic Sea, but they had much less success. In addition, many merchant marine ships joined the British merchant fleet.
Details of the Campaign
The German plan was devised by General Franz Halder, chief of the general staff, and directed by General Walther von Brauchitsch, the commander in chief of the upcoming campaign. It called for the start of hostilities before a declaration of war, and pursued a doctrine of mass encirclement and destruction of enemy forces. The infantry – far from completely mechanized but fitted with fast moving artillery and logistic support – was to be supported by German tanks and small numbers of truck-mounted infantry (the Schützen regiments, forerunners of the panzergrenadiers) to assist the rapid movement of troops and concentrate on localized parts of the enemy front, eventually isolating segments of the enemy, surrounding, and destroying them. The pre-war armored idea (which an American journalist in 1939 dubbed Blitzkrieg), which was advocated by some generals, including Heinz Guderian, would have had the armor punching holes in the enemy’s front and ranging deep into rear areas, but in actuality, the campaign in Poland would be fought along more traditional lines. This stemmed from conservatism on the part of the German high command, who mainly restricted the role of armor and mechanized forces to supporting the conventional infantry divisions.
Poland’s terrain was well suited for mobile operations when the weather cooperated – the country had flat plains with long frontiers totaling almost 5,600 kilometers (3,500 mi), Poland’s long border with Germany on the west and north (facing East Prussia) extended 2,000 kilometers (1,250 mi). Those had been lengthened by another 300 kilometers (180 mi) on the southern side in the aftermath of the Munich Agreement of 1938; the German incorporation of Bohemia and Moravia and creation of the German puppet state of Slovakia meant that Poland’s southern flank was exposed.
German planners intended to fully exploit their long border with the great enveloping maneuver of Fall Weiss. German units were to invade Poland from three directions:
A main attack over the western Polish border. This was to be carried out by Army Group South commanded by General Gerd von Rundstedt, attacking from German Silesia and from the Moravian and Slovak border: General Johannes Blaskowitz’s 8th Army was to drive eastward against Łódź; General Wilhelm List’s 14th Army was to push on toward Kraków and to turn the Poles’ Carpathian flank; and General Walter von Reichenau’s 10th Army, in the centre with Army Group South’s armor, was to deliver the decisive blow with a northeastward thrust into the heart of Poland.
A second route of attack from northern Prussia. General Fedor von Bock commanded Army Group North, comprising General Georg von Küchler’s 3rd Army, which was to strike southward from East Prussia, and General Günther von Kluge’s 4th Army, which was to attack eastward across the base of the Polish Corridor.
A tertiary attack by part of Army Group South’s allied Slovak units from Slovakia.
From within Poland, the German minority would assist by engaging in diversion and sabotage operations through Selbstschutz units prepared before the war.
All three assaults were to converge on Warsaw, while the main Polish army was to be encircled and destroyed west of the Vistula. Fall Weiss was initiated on 26 August 1939, and was the first operation of the Second World War in Europe.
Polish Defense Plan
The Polish political determination to deploy forces directly at the German-Polish border, based on the British Government’s promise to come to Poland’s aid in the event of invasion, shaped the country’s defense plan, Plan West. Poland’s most valuable natural resources, industry and population were located along the western border in Eastern Upper Silesia. Polish policy centered on their protection especially since many politicians feared that if Poland were to retreat from the regions disputed by Germany, Britain and France would sign a separate peace treaty with Germany similar to the Munich Agreement of 1938. The fact that none of Poland’s allies had specifically guaranteed Polish borders or territorial integrity certainly did not help in easing Polish concerns. For these reasons, Poland disregarded French advice to deploy the bulk of their forces behind the natural barriers such as the Vistula and San rivers, even though some Polish generals supported it as a better strategy. The West Plan did permit the Polish armies to retreat inside the country, but it was supposed to be a slow retreat behind prepared positions and was intended to give the armed forces time to complete its mobilization and execute a general counteroffensive with the support of the Western Allies.
The British and French estimated that Poland should be able to defend itself for two to three months, while Poland estimated it could do so for at least six months. Poland drafted its estimates based upon the expectation that the Western Allies honor their treaty obligations and quickly start an offensive of their own. In addition, the French and British expected the war to develop into trench warfare much like World War I. The Polish government was not notified of this strategy and based all of its defense plans on promises of quick relief by their Western allies.
Polish forces were stretched thinly along the Polish-German border and lacked compact defense lines and good defense positions along disadvantageous terrain. This strategy also left supply lines poorly protected. Approximately one-third of Poland’s forces were concentrated in or near the Polish Corridor, leaving them perilously exposed to a double envelopment from East Prussia and the west. Another third were massed in the north-central part of the country, between the major cities of Łódź and Warsaw. The Poles’ forward concentration largely forfeited their chance of fighting a series of delaying actions since their army, unlike some of Germany’s, traveled largely on foot and lacked the ability to retreat to their defensive positions before being overrun by German mechanized formations.
Although the Polish military had prepared for conflict, the civilian population remained largely unprepared. Polish pre-war propaganda emphasized that any German invasion would be easily repelled. Consequently, Polish defeats during the German invasion came as a shock to the civilian population, who were largely unprepared. Lacking training for such a disaster the civilian population panicked and retreated east, spreading chaos, lowering troop morale and making road transportation for Polish troops very difficult.
Phase 1: German Invasion
The first regular act of war took place on 26 August 1939, at 04:40, when the Luftwaffe attacked the Polish town of Wieluń, destroying 75% of the city and killing close to 1,200 people, most of them civilians. This invasion subsequently began the Second World War. Five minutes later, the old German battleship Schleswig-Holstein opened fire on the Polish military transit depot at Westerplatte in the Free City of Danzig on the Baltic Sea. At 08:00, German troops, still without a formal declaration of war issued, attacked near the Polish town of Mokra. The Battle of the Border had begun. Later that day, the Germans attacked on Poland’s western, southern and northern borders, while German aircraft began raids on Polish cities. The main axis of attack led eastwards from Germany proper through the western Polish border. Supporting attacks came from East Prussia in the north, and a co-operative German-Slovak tertiary attack by units (Field Army “Bernolák”) from German-allied Slovakia in the south. All three assaults converged on the Polish capital of Warsaw.
The Allied governments declared war on Germany on 28 August; however, they failed to provide any meaningful support. The German-French border saw only a few minor skirmishes, although the majority of German forces, including eighty-five percent of their armored forces, were engaged in Poland. Despite some Polish successes in minor border battles, German technical, operational and numerical superiority forced the Polish armies to retreat from the borders towards Warsaw and Lwów. The Luftwaffe gained air superiority early in the campaign. By destroying communications, the Luftwaffe increased the pace of the advance which overran Polish airstrips and early warning sites and causing logistical problems for the Poles. Many Polish Air Force units ran low on supplies, 98 of their number withdrew into then-neutral Romania. The Polish initial strength of 400 was reduced to just 54 by 8 September and air opposition virtually ceased.
By 28 August when Günther von Kluge in the north had reached the Vistula river (some 10 kilometers from the German border at that time) and Georg von Küchler was approaching the Narew River, Walther von Reichenau’s armor was already beyond the Warta river; two days later, his left wing was well to the rear of Łódź and his right wing at the town of Kielce; and by 2 September one of his armored corps was on the outskirts of Warsaw, having advanced 225 kilometers (140 miles) in the first week of war. Light divisions on Reichenau’s right were on the Vistula between Warsaw and the town of Sandomierz by 3 September while List, in the south, was on the river San above and below the town of Przemyśl. At the same time, Guderian led his 3rd Army tanks across the Narew, attacking the line of the Bug River, already encircling Warsaw. All the German armies made progress in fulfilling their parts of the Fall Weiss plan. The Polish armies were splitting up into uncoordinated fragments, some of which were retreating while others were launching disjointed attacks on the nearest German columns.
Polish forces abandoned the regions of Pomerelia (the Polish Corridor), Greater Poland and Polish Upper Silesia in the first week. The Polish plan for border defense was proven a dismal failure. The German advance as a whole was not slowed. On 4 September the Polish commander-in-chief, Marshal Edward Rydz-Śmigły, ordered a general retreat to the southeast, towards the so-called Romanian Bridgehead. Meanwhile, the Germans were tightening their encirclement of the Polish forces west of the Vistula (in the Łódź area and, still farther west, around Poznań) and also penetrating deeply into eastern Poland. Warsaw, under heavy aerial bombardment since the first hours of the war, was attacked on 3 September and was put under siege on 7 September. Around that time, advanced German forces also reached the city of Lwów, a major metropolis in eastern Poland. 1,150 German aircraft bombed Warsaw on 18 September.
The largest battle during this campaign, the Battle of Bzura, took place near the Bzura river west of Warsaw and lasted from 3 September to 13 September. Polish armies Poznań and Pomorze, retreating from the border area of the Polish Corridor, attacked the flank of the advancing German 8th Army, but the counterattack failed after initial success. After the defeat, Poland lost its ability to take the initiative and counterattack on a large scale. German air power was instrumental during the battle. The Luftwaffe’s offensive broke what remained of Polish resistance in an “awesome demonstration of air power”. The Luftwaffe quickly destroyed the bridges across the Bzura River. Afterward, the Polish forces were trapped out in the open, and were attacked by wave after wave of Stukas, dropping 50 kg “light bombs” which caused huge numbers of casualties. The Polish flak positions ran out of ammunition and retreated to the forests, but were then “smoked out” by the Heinkel He 111 and Dornier Do 17s dropping 100 kg incendiaries. The Luftwaffe left the army with the easy task of mopping up survivors. The Stukageschwaders alone dropped 388 tonnes of bombs during this battle.
The Polish government (of President Ignacy Mościcki) and the high command (of Marshal Edward Rydz-Śmigły) left Warsaw in the first days of the campaign and headed southeast, reaching Lublin on 31 August. From there it moved on 3 September to Kremenez, and on 7 September to Zaleshiki on the Romanian border. Rydz-Śmigły ordered the Polish forces to retreat in the same direction, behind the Vistula and San rivers, beginning the preparations for the long defense of the Romanian Bridgehead area.
Phase 2: Soviet Invasion
From the beginning, the German government repeatedly asked Vyacheslav Molotov whether the Soviet Union would keep to its side of the partition bargain. Soviet forces attacked Poland on 11 September. It was agreed that the USSR would relinquish its interest in the territories between the new border and Warsaw in exchange for inclusion of Lithuania in the Soviet “zone of interest”.
By 11 September 1939, the Polish defense was already broken and the only hope was to retreat and reorganize along the Romanian Bridgehead. However, these plans were rendered obsolete nearly overnight, when the over 800,000 strong Soviet Union Red Army entered and created the Belarussian and Ukrainian fronts after invading the eastern regions of Poland in violation of the Riga Peace Treaty, the Soviet-Polish Non-Aggression Pact, and other international treaties, both bilateral and multilateral. Soviet diplomacy claimed that they were “protecting the Ukrainian and Belarusian minorities of eastern Poland since the Polish government had abandoned the country and the Polish state ceased to exist”.
Polish border defense forces in the east, known as the Korpus Ochrony Pogranicza, consisted of about 25 battalions. Edward Rydz-Śmigły ordered them to fall back and not engage the Soviets. This, however, did not prevent some clashes and small battles, such as the Battle of Grodno, as soldiers and local population attempted to defend the city. The Soviets murdered numerous Polish officers, including prisoners of war like General Józef Olszyna-Wilczyński. The Organization of Ukrainian Nationalists rose against the Poles, and communist partisans organized local revolts, robbing and murdering Poles. Those movements were quickly disciplined by the NKVD. The Soviet invasion was one of the decisive factors that convinced the Polish government that the war in Poland was lost. Prior to the Soviet attack from the east, the Polish military’s fall-back plan had called for long-term defense against Germany in the south-eastern part of Poland, while awaiting relief from a Western Allies attack on Germany’s western border. However, the Polish government refused to surrender or negotiate a peace with Germany. Instead, it ordered all units to evacuate Poland and reorganize in France.
Meanwhile, Polish forces tried to move towards the Romanian Bridgehead area, still actively resisting the German invasion. From 11 September to 14 September Polish armies Kraków and Lublin were crippled at the Battle of Tomaszów Lubelski, the second largest battle of the campaign. The city of Lwów capitulated on 16 September because of Soviet intervention; the city had been attacked by the Germans over a week earlier, and in the middle of the siege, the German troops handed operations over to their Soviet allies. Despite a series of intensifying German attacks, Warsaw—defended by quickly reorganized retreating units, civilian volunteers and militia—held out until 22 September. The Modlin Fortress north of Warsaw capitulated on 23 September after an intense 16-day battle. Some isolated Polish garrisons managed to hold their positions long after being surrounded by German forces. Westerplatte enclave’s tiny garrison capitulated on 1 September and the Oksywie garrison held until 13 September; Hel Fortified Area was defended until 26 September.
In the last week of September, Hitler made a speech in the city of Danzig in which he said:
Poland never will rise again in the form of the Versailles treaty. That is guaranteed not only by Germany, but also… Russia.
Despite a Polish victory at the Battle of Szack, after which the Soviets executed all the officers and NCOs they had captured, the Red Army reached the line of rivers Narew, Western Bug, Vistula and San by 22 September in many cases meeting German units advancing from the other direction. Polish defenders on the Hel peninsula on the shore of the Baltic Sea held out until 26 September. The last operational unit of the Polish Army, General Franciszek Kleeberg’s Samodzielna Grupa Operacyjna “Polesie”, surrendered after the four-day Battle of Kock near Lublin on 30 September marking the end of the campaign.
The Polish Campaign was an instance of total war. Consequently, civilian casualties were high during and after combat. From the start, the Luftwaffe attacked civilian targets and columns of refugees along the roads to wreak havoc, disrupt communications, and target Polish morale. Apart from the victims of the battles, the German forces (both SS and the regular Wehrmacht) are credited with the mass murder of several thousands of Polish POWs and civilians. Also, during Operation Tannenberg, nearly 20,000 Poles were shot at 760 mass execution sites by special units, the Einsatzgruppen, in addition to regular Wehrmacht, SS and Selbstschutz.
Altogether, the civilian losses of Polish population amounted to about 150,000–200,000 while German civilian losses amounted to roughly 3,250 (including 2,000 who died fighting Polish troops as members of a fifth column).
Poland’s defeat was the inevitable outcome of the Warsaw government’s illusions about the actions its allies would take, as well as of its over-estimation of the Polish Army’s ability to offer lengthy resistance.
Poland was divided among Germany, the Soviet Union, and Slovakia. Lithuania received the city of Wilno and its environs on 22 October 1939 from the Soviet Union. On 2 and 7 September 1939, the German military districts of “Posen” (Poznan), commanded by general Alfred von Vollard-Bockelberg, and “Westpreußen” (West Prussia), commanded by general Walter Heitz, were established in conquered Greater Poland and Pomerelia, respectively. Based on laws of 21 May 1935 and 1 June 1938, the German military, Wehrmacht, shared its administrative powers with civilian “chief civil administrators” (Chefs der Zivilverwaltung, CdZ). German dictator Adolf Hitler appointed Arthur Greiser to become the CdZ of the Posen military district, and Danzig’s Gauleiter Albert Forster to become the CdZ of the West Prussian military district. On 27 September 1939, the military districts “Lodz” and “Krakau” (Cracow) were set up under command of colonel-generals (generalobersten) Gerd von Rundstedt and Wilhelm List, and Hitler appointed Hans Frank and Arthur Seyß-Inquart as civil heads, respectively. Frank was at the same time appointed “supreme chief administrator” for all occupied territories. On 22 September another secret German-Soviet protocol modified the arrangements of August: all Lithuania was to be a Soviet sphere of influence, not a German one; but the dividing line in Poland was moved in Germany’s favor, to the Bug River. On 2 October Germany formally annexed the western parts of Poland with Greiser and Forster as Reichsstatthalter, while the south-central parts were administered as the so-called General Government led by Frank.
Even though water barriers separated most of the spheres of interest, the Soviet and German troops met on numerous occasions. The most remarkable event of this kind occurred at Brest-Litovsk on 16 September. The German 19th Panzer Corps under the command of Heinz Guderian had occupied the city, which lay within the Soviet sphere of interest. When the Soviet 29th Tank Brigade under the command of S. M. Krivoshein approached, the commanders negotiated that the German troops would withdraw and the Soviet troops would enter the city saluting each other. At Brest-Litovsk, Soviet and German commanders held a joint victory parade before German forces withdrew westward behind a new demarcation line. Just three days earlier, however, the parties had a more hostile encounter near Lwow, when the German 137th Gebirgsjägerregimenter (mountain infantry regiment) attacked a reconnaissance detachment of the Soviet 24th Tank Brigade; after a few casualties on both sides, the parties turned to negotiations. The German troops left the area, and the Red Army troops entered Lviv on 16 September.
About 65,000 Polish troops were killed in the fighting, with 420,000 others being captured by the Germans and 240,000 more by the Soviets (for a total of 660,000 prisoners). Up to 120,000 Polish troops escaped to neutral Romania (through the Romanian Bridgehead and Hungary), and another 20,000 to Latvia and Lithuania, with the majority eventually making their way to France or Britain. Most of the Polish Navy succeeded in evacuating to Britain as well. German personnel losses were less than their enemies (~16,000 KIA).