Invasion of Poland (1939)

The **invasion of Poland** in 1939 was a military offensive in which Nazi Germany and, two weeks later, the Soviet Union invaded Poland. That was the start of World War II in Europe.

The invasion started on 1 September 1939. The invasion of Poland caused the United Kingdom and France to declare war on Germany on 3 September, but they did little to affect the September Campaign. The fighting ended on 6 October, Germany and the Soviet Union had conquered Poland and divided it according to their Molotov-Ribbentrop pact.

It is often called the first time that blitzkrieg was tried on the battlefield, but similar methods had been used earlier. The German surprise attack was successful and was very effective against the ineffective and demobilized Polish Army, whose tanks and airplanes were few and mostly old. The Poles were outflanked, outmaneuvered, and outnumbered in September 1939 and easily destroyed by the Germans. The Poles, if they had been well prepared, could have had two million soldiers fighting.

In the first few days of the German invasion, Poland proved to be more difficult to invade than the Germans had expected. In the Battle of Mokra, on 2 September, the Poles repulsed an attack by a German Panzer division and forced its retreat. The Luftwaffe, unlike during the Germans' invasions of other countries, did not easily overcome the outnumbered Polish Air Force. However, the Germans' great superiority in numbers made them gain air superiority after five to six days.

Surrounded by German territories north, west, and south of Poland, the Poles had little space for tactical retreat. The Germans reached Warsaw and attacked on 7 September but were repulsed. They had suffered heavy tank losses and so were forced to retreat.

The Battle of Bzura, on 9 September, was the largest attack by the Poles during the war. The Poles had great initial success by decimating two German divisions and taking 3,500 German prisoners. The Polish infantry fought well, but by 19 September, the overwhelming German reinforcements had defeated the Poles.

The Poles realized the British and French were in the Phoney War and had no intention of assisting Poland, and the Soviet Red Army invaded Poland from the east on 17 September. The Polish High Command ordered the troops and equipment to the Romanian Bridgehead to enter Romania with the intention to continue their resistance by moving as much of their army to France as possible. Most of the Polish Navy escaped to Britain. Polish cryptographers who had cracked the German Enigma machine went to France and later to Britain to continue their work.

Polish politicians set up a government-in-exile in France and later escaped to Britain. In 1945, when the Allied armies invaded Germany and forced its surrender, the Polish Army was the fourth-largest Allied army.

## Infobox (military conflict)

- **partof**: World War II
- **image**: Second World War Europe.png
- **caption**: The map shows the beginning of the Second World War in September 1939 in a wider European context.
- **date**: 1 September – 6 October 1939
- **place**: Second Polish Republic, Poland
- **result**: Decisive German/Slovak and Soviet victory.
Beginning of World War II.
- **territory**: Polish territory divided between Germany, the Soviet Union, Lithuania and Slovakia
- **combatant1**: *  Slovak Republic (1939–1945), Slovakia
 Soviet Union <small>(After 17 September, see Soviet invasion of Poland, details)</small>
- **combatant2**: Second Polish Republic, Poland
- **commander1**: Fedor von Bock
<small>(Army Group North)</small>

Gerd von Rundstedt
<small>(Army Group South)</small>

Ferdinand Čatloš
<small>(Field Army Bernolák, Army Bernolák)</small>

---
 Kliment Voroshilov
<small>(Belarusian Front (1939), Belorussian Front)</small>

Mikhail Kovalev
<small>(Belorussian Front (1939), Belorussian Front)</small>

Semyon Timoshenko
<small>(Ukrainian Front (1939), Ukrainian Front)</small>
- **commander2**: Edward Rydz-Śmigły
- **strength1**: **Germany**:
60 divisions,
6 brigades,
9,000 guns,
2,750 tanks,
2,315 aircraft
**Slovakia**:
3 divisions

**17 September:**

**Soviet Union**:
33+ divisions,
11+ brigades,
4,959 guns,
4,736 tanks,
3,300 aircraft

---
**Total**:
1,500,000 Germans,
 466,516 Soviets,
 51,306 Slovaks
 **Grand total: 2,000,000+**
- **strength2**: **Poland**:
39 divisions (some of them were never fully mobilized and concentrated),
 16 brigades,
4,300 guns,
880 tanks,
400 aircraft
 **Total: 950,000**
- **casualties1**: **Germany**:
16,343 killed,
3,500 missing,
30,300 wounded
**Slovakia**:
37 killed,
11 missing,
114 wounded

---
**USSR**:
1,475 killed or missing,
2,383 wounded
- **casualties2**: **Poland**:
66,000 dead,
133,700 wounded,
694,000 captured
- **conflict**: Invasion of Poland