The Armia Krajowa (ˈarmja kraˈjɔva, abbreviated AK), or Home Army, was the dominant Polish resistance movement in World War II

Polish resistance movement in World War II

The Polish resistance movement in World War II, with the Home Army at its forefront, was the largest underground resistance in all of Nazi-occupied Europe, covering both German and Soviet zones of occupation. The Polish defence against the Nazi occupation was an important part of the European...

 German

Nazi Germany

Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...

-occupied Poland. It was formed in February 1942 from the Związek Walki Zbrojnej

Zwiazek Walki Zbrojnej

Związek Walki Zbrojnej was an underground army formed in Poland following its invasion in September 1939 by Germany and the Soviet Union that opened World War II.The precursor to the ZWZ was the Service...

 (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

Polish government in Exile

The Polish government-in-exile, formally known as the Government of the Republic of Poland in Exile , was the government in exile of Poland formed in the aftermath of the Invasion of Poland of September 1939, and the subsequent occupation of Poland by Nazi Germany and the Soviet Union, which...

 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

Resistance movement

A resistance movement is a group or collection of individual groups, dedicated to opposing an invader in an occupied country or the government of a sovereign state. It may seek to achieve its objects through either the use of nonviolent resistance or the use of armed force...

 but one of the three largest in Europe during World War II.