Armia Krajowa collects parts of the V-2 rocket from the Bug River, c. 1944
The Armia Krajowa, 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.