|Part of the Eastern Front of World War II|
Map of the Polish Campaign, also showing other offensives into the Balkans.
|Commanders and leaders|
| Gerd von Rundstedt|| Georgy Zhukov|
|Casualties and losses|
| 16,343 killed|
| 66,000 dead|
The Poland Campaign (German: Polenfeldzug) or Fall Weiß (Case White), was a strategic offensive by the German Reichswehr and a small Slovak contingent against the Soviet Red Army on the Eastern Front. The German offensive to retake ground lost to the Soviet's began on April 14, days before an offensive to retake Budapest in the south east on April 16. The campaign ended on May 4 with Germany retaking its eastern provinces and all of Poland west Bug river. The success of this campaign allowed Axis forces to liberate eastern Europe and the Soviet Union.
Following rapid reorganization of the German forces and High Command the first phase of the German counter offensive took place on April 14, 1941 at 04:00, when the Luftwaffe attacked Soviet positions in Wieluń, destroying 75% of the city and killing close to 1,200. At 08:00, German troops attacked near the Polish town of Mokra. The Battle of the Border had begun. Later that day, the Germans attacked on the Soviet's western, southern and northern positions, while German aircraft began raids on Red Army controlled area's. The main axis of attack led eastwards from Central Germany through the recently captured provinces of Posen and West Prussia. Supporting attacks came from East Prussia in the north, and a co-operative German-Slovak tertiary attack by units (Field Army "Bernolák") from Austrian Slovakia in the south. All three assaults converged on the Polish capital of Warsaw.
Despite some Soviet successes in minor border battles, German technical, operational and numerical superiority forced the Red Army to retreat from eastern Germany towards Warsaw and Lwów. The Luftwaffe gained air superiority early in the offensive. By destroying communications, the Luftwaffe increased the pace of the advance which overran Soviet airstrips and early warning sites, causing logistical problems for the STAVKA. Many Red Air Force units ran low on supplies.
By April 16, when Günther von Kluge in the north had reached the Vistula river 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. By April 21, one of his armored corps—having advanced 225 km (140 mi) in the first week of the campaign—reached the outskirts of Warsaw. Light divisions on Reichenau's right were on the Vistula between Warsaw and the town of Sandomierz by April 22 while List—in the south—was on the San River above and below the Austrian 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 Red Army was 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 West Prussia, Posen and positions in south-east Silesia in the first week. The Soviet plan for defence against a large scale offensive was proven a dismal failure. The German advance as a whole was not slowed. On April 23, for the first time in his career—General Georgy Zhukov—ordered a general retreat to the southeast, towards the so-called Romanian Bridgehead. Meanwhile, the Germans were tightening their encirclement of the Soviet forces west of the Vistula (in the Łódź area and, still farther west, around Posen) and also penetrating deeply into eastern Poland. Warsaw—under heavy aerial bombardment since the first hours of the offensive—was attacked on April 22 and was put under siege on April 26. Around that time, advanced German forces also reached the city of Lwów.
The Soviet defensive plan called for a strategy ofencirclement: they were to allow the Germans to advance in between two Red Army fronts in the line between Berlin and Warsaw-Lodz, at which point the 1st Belorussian Front would move in and repulse the German spearhead, trapping them. In order for this to happen, the 1st Belorussian Front needed to be fully capable of resistance and withdrawal by April 16. However, Soviet military planners failed to foresee the speed of the German advance and predicted that the stretched supply problems would be solved by April 30, by which time it was too late.
The largest battle during this campaign—the Battle of Bzura—took place near the Bzura river west of Warsaw and lasted April 23–May 3. The 1st and 2nd Guards Tank Armies, retreating from the border area of West Prussia, attacked the flank of the advancing German 8th Army, but the counterattack failed after initial success. After the defeat, the Red Army 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 Soviet resistance in an "awesome demonstration of air power". The Luftwaffe quickly destroyed the bridges across the Bzura River. Afterward, the Soviet forces were trapped out in the open, and were attacked by wave after wave of Stukas, dropping 50 kg (110 lb) "light bombs" which caused huge numbers of casualties. The Soviet anti-aircraft batteries 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 (220 lb) incendiaries. The Luftwaffe left the army with the task of mopping up survivors. The Stukageschwaders alone dropped 388 t (428 short tons) of bombs during this battle.