All about Invasion of Poland – (04)…
Details of the campaign…
The German plan for what became known as the September Campaign 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 totalling almost 5,600 kilometres (3,500 mi), Poland’s long border with Germany on the west and north (facing East Prussia) extended 2,000 kilometres (1,250 mi). Those had been lengthened by another 300 kilometres (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 manoeuvre 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 armour, 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 1 September 1939, and was the first operation of the Second World War in Europe.
Polish defence 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 defence plan, Plan West. Poland’s most valuable natural resources, industry and population were located along the western border in Eastern Upper Silesia. Polish policy centred 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 orterritorial 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 theWestern 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 defence plans on promises of quick relief by their Western allies.
Polish forces were stretched thinly along the Polish-German border and lacked compact defence lines and good defence 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.
As the prospect of conflict increased, the British government pressed Marshal Edward Rydz-Śmigły, to evacuate the most modern elements of the Polish Navy from the Baltic Sea. In the event of war the Polish military leaders realized that the ships which remained in the Baltic were likely to be quickly sunk by the Germans. Furthermore, the Danish straits were well within operating range of the German Kriegsmarine andLuftwaffe, so there was little chance of an evacuation plan succeeding if implemented after hostilities began. Four days after the signing of thePolish-British Common Defence Pact, three destroyers of the Polish Navy executed the Peking Plan and consequently evacuated to Great Britain.
Although the Polish military had prepared for conflict, the civilian population remained largely unprepared. Polish pre-war propagandaemphasized 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…
Following several German-staged incidents (like the Gleiwitz incident, a part of Operation Himmler), which German propaganda used as an excuse to claim that German forces were acting in self-defence, the first regular act of war took place on 1 September 1939, at 04:40, when the German Air Force (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 pre-dreadnought 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 Borderhad 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-alliedSlovakia in the south. All three assaults converged on the Polish capital of Warsaw.
The Allied governments declared war on Germany on 3 September; 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 armoured 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 Luftwaffegained 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, 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 14 September and air opposition virtually ceased.
By 3 September when Günther von Kluge in the north had reached the Vistula river (some 10 kilometres from the German border at that time) and Georg von Küchler was approaching the Narew River, Walther von Reichenau’s armour 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 8 September one of his armoured corps was on the outskirts of Warsaw, having advanced 225 kilometres (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 9 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 defence was proven a dismal failure. The German advance as a whole was not slowed. On 10 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 9 September and was put under siege on 13 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 24 September.
The largest battle during this campaign, the Battle of Bzura, took place near the Bzura river west of Warsaw and lasted from 9 September to 19 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 6 September. From there it moved on 9 September to Kremenez, and on 13 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 defence of the Romanian Bridgehead area.