Military history of Poland during World War II
The European Theatre of World War II opened with the German invasion of Poland on Friday the 1st of September 1939. The Soviets invaded Poland on September 17 as had been agreed with Nazi Germany in the Molotov-Ribbentrop Pact. On the 6th of October, following the Polish defeat at the Battle of Kock, German and Soviet forces gained full control over Poland. The success of the invasion marked the end of the Second Polish Republic, though Poland never formally surrendered.
German losses included about 16,000 killed in action, 28,000 wounded, 3,500 missing, over 200 aircraft, and 30% of their armored vehicles. The Polish casualties were about 66,000 dead and 694,000 captured. A campaign that lasted about a month consumed eight months worth of supplies for the Germans. Hitler had gambled incorrectly that France and Britain would allow him to annex parts of Poland without military reaction. The United Kingdom and France declared war on Germany on September 3.
A substantial number of Poles risked their lives in the German occupation to save Jews. German-occupied Poland was the only European territory where the Germans punished any kind of help to Jews with death for the helper and his entire family. Even so, Poland was also the only German-occupied country to establish an organization specifically to aid Jews. Known by the cryptonym Żegota, it provided food, shelter, medical care, money, and false documents to Jews.
The main resistance force in German-occupied Poland was the Armia Krajowa or Home Army which numbered some 400,000 fighters at its peak as well as many more sympathizers. Throughout most of the war, AK was one of the three largest resistance movements in the war. Its combat activity was low until 1943 as the army was avoiding suicidal warfare and preserved its very limited resources for later conflicts. Then the AK started a nationwide uprising known as Operation Tempest against Nazi forces. Before that, AK units carried out thousands of raids, intelligence operations, bombed hundreds of railway shipments, participated in many clashes and battles with the German police and Wehrmacht units and conducted tens of thousands of acts of sabotage against German industry.
In a period of more than six and a half years from late December 1932 to the outbreak of World War II, three mathematician-cryptologists Marian Rejewski, Henryk Zygalski and Jerzy Różycki developed techniques to decrypt messages produced on the German Enigma cipher machine. Just five weeks before the outbreak of World War II on the 25th of July 1939 near Pyry in the Kabaty Woods south of Warsaw Poland disclosed her achievements to France and the United Kingdom.
Polish intelligence supplied valuable intelligence to the Allies with 48% of all reports received by the British secret services from continental Europe between 1939 and 1945 coming from Polish sources. The total number of those reports is estimated at 80,000 and 85% of them were deemed high or better quality. As early as 1940 Polish agents including Witold Pilecki penetrated German concentration camps including Auschwitz and informed the world about Nazi atrocities. Jan Karski reported to the Polish government in exile and the Western Allies on the situation in German-occupied Poland especially the destruction of the Warsaw Ghetto.
After the country's defeat in the 1939 campaign the Polish government in exile quickly organized in France a new army of about 75,000 men. By the fall of France numerous Polish personnel had died in the fighting or had been interned in Switzerland. Nevertheless about 19,000 Polish soldiers evacuated from France most alongside other troops transported from western France to the United Kingdom.
In 1941 following an agreement between the Polish government in exile and Joseph Stalin the Soviets released Polish citizens from whom a 75,000-strong army was formed in the USSR under General Władysław Anders. Without any support from the Soviets to train equip and maintain this army the Polish government in exile followed Anders' advice for a transfer of some 20,000 soldiers and about 10,000 civilians across the Caspian Sea to Iran permitting Soviet divisions in occupation there to be released for action. In the Middle East this Anders' Army joined the British Eighth Army where it formed Polish II Corps.
After the Polish government-in-exile organized the Anders Army in 1941 in the Soviet Union in the aftermath of Operation Barbarossa and evacuated it to the West Polish communists sought to create a new army under communist control out of the many ethnic Poles that remained in the Soviet Union. These were primarily citizens of the prewar Second Polish Republic that had been deported and often imprisoned by the Soviets following the Soviet annexation of Poland's eastern territories as per the Molotov-Ribbentrop Pact.
The Soviet Union created the Union of Polish Patriots or ZPP in 1943 a communist Polish organization intended to represent the interest of Poles on Soviet soil and organize this new army. The relocated Poles along with numbers of Byelorussians Ukrainians and Polish Jews were organized into a division the nucleus of a force known as the Polish People's Army Ludowe Wojsko Polskie but colloquially known as the Berling Army after its first commander Zygmunt Berling. The division made its combat debut in October 1943 at the Battle of Lenino.
Józef Kosacki invented the Polish mine detector which would be used by the Allies from 1942. The Vickers Tank Periscope MK.IV was invented by engineer Rudolf Gundlach and patented in 1936 as the Gundlach Peryskop obrotowy. Initially it was mounted in Polish tanks such as the 7TP and TKS. Subsequently the design patent was sold to the British for a nominal sum and used in most tanks of World War II including the Soviet T-34 the British Crusader Churchill Valentine and Cromwell tanks and the American M4 Sherman.
The main advantage of the periscope was that the tank commander no longer had to turn his head in order to look backwards. The design was also later used extensively by the Germans. Henryk Magnuski a Polish engineer working for Motorola co-designed the SCR-300 radio in 1940. It was the first small radio receiver/transmitter to have manually set frequencies. It was used extensively by the American Army and was nicknamed the walkie-talkie.
Common questions
When did the German invasion of Poland begin and end?
The European Theatre of World War II opened with the German invasion of Poland on Friday the 1st of September 1939. On the 6th of October, following the Polish defeat at the Battle of Kock, German and Soviet forces gained full control over Poland.
How many casualties did Poland suffer during the 1939 campaign?
Polish casualties were about 66,000 dead and 694,000 captured during the campaign that lasted about a month. The success of the invasion marked the end of the Second Polish Republic though Poland never formally surrendered.
What organization did Poland establish to aid Jews under German occupation?
Poland was the only German-occupied country to establish an organization specifically to aid Jews known by the cryptonym Żegota. It provided food, shelter, medical care, money, and false documents to Jews despite death penalties for helpers.
Who developed Enigma decryption techniques before World War II began?
Three mathematician-cryptologists Marian Rejewski, Henryk Zygalski and Jerzy Różycki developed techniques to decrypt messages produced on the German Enigma cipher machine from late December 1932 to the outbreak of World War II. They disclosed their achievements to France and the United Kingdom on the 25th of July 1939 near Pyry in the Kabaty Woods south of Warsaw.
Which Polish squadron claimed the highest number of kills during the Battle of Britain?
The Polish 303 Fighter Squadron claimed the highest number of kills of any Allied squadron during the Battle of Britain. A total of 145 Polish pilots defended British skies including those fighting in British squadrons alongside the four Polish squadrons that took part in the battle.