The Armia Krajowa (Polish pronunciation: [ˈarmja kraˈjɔva], abbreviated AK), or Home Army, was the dominant Polish resistance movement in World War II German-occupied Poland. It was formed in February 1942 from the Związek Walki Zbrojnej (Union for Armed Struggle). Over the next two years, it absorbed most other Polish underground forces. It was loyal to the Polish government in exile and constituted the armed wing of what became known as the "Polish Underground State." Estimates of its membership in 1944 range from 200,000 to 600,000, with the most common number being 400,000; that figure would make it not only the largest Polish underground resistance movement but one of the three largest in Europe during World War II. It was disbanded on January 20, 1945, when Polish territory had been mostly cleared of German forces by the advancing Soviet Red Army.

The AK's primary resistance operations were the sabotage of German activities, including transports headed for the Eastern Front in the Soviet Union. The AK also fought several full-scale battles against the Germans, particularly in 1943 and 1944 during Operation Tempest. They tied down significant German forces, diverting much-needed supplies, while trying to support the Soviet military.

Jan Piwnik (1912–1944) was a Polish World War II soldier, a cichociemny and a notable leader of the Home Army in the Świętokrzyskie Mountains. He used the noms de guerre Ponury ("Gloomy" or "Grim") and Donat.

Jan Piwnik was born August 12, 1912 in the village of Janowice near Ostrowiec Świętokrzyski. In 1933, he graduated from a reserve NCO artillery school in Włodzimierz Wołyński. In 1935, he joined the Polish police, where he served as an officer.

Mobilized in 1939, during the invasion of Poland by Germany, he commanded a motorized unit of the police. When the Soviets also attacked, on September 23, he and his unit crossed the Hungarian border and were interned.

Piwnik managed to escape from the internment camp. In November 1939, he reported to the Polish Government in Exile in Paris. He joined the Polish Army, reconstituted in France at that time and was assigned to the 4th Rifle Brigade (en cadre). After evacuation to Great Britain following the fall of France, he joined the Polish 1st Independent Parachute Brigade under General Stanisław Sosabowski.

Zbigniew 'Bob' Kabata, CM (born 17 March 1924) is a highly respected parasitologist, veteran of the Polish Armia Krajowa during World War II,poet, fisherman, translator and scientific administrator.

Kabata was born into a military family in Jeremicze, Poland on 17 March 1924. He entered the Marshal Józef Piłsudski Military Academy in Lwów as a cadet in 1937.

After the invasion of Poland by Nazi forces in 1939, Kabata joined the Armia Krajowa and fought against the occupying forces. His unit became famous after assaults on two Gestapo jails, which resulted in the liberation of about 200 prisoners. Kabata was cited several times for bravery. During his time in the resistance, Kabata wrote several patriotic poems honouring the Polish armed forces. His most famous work, The Underground Army, became the unofficial anthem of the Polish combatant community and is inscribed on numerous Polish war memorials.

Following the defeat of Nazi forces in Poland, Kabata made a daring escape across Soviet lines to join up with the Polish 2nd Army Corps in Italy and commanded a rifle platoon in the 3rd Company, 1st Carpathian Rifles (the famous "Tobruk Rats").