Union of Armed Struggle

The government in exile created the ZWZ to bring the underground in Poland under its control and to limit the influence of officers linked to the Sanation regime. Its commander-in-chief was General Kazimierz Sosnkowski, based in France, and the country was split into two zones: the German one, commanded from Warsaw by Colonel Stefan Rowecki 'Grot', and the Soviet one, whose command in Lwów was to be taken by General Michał Karaszewicz-Tokarzewski, who was instead arrested by the NKVD. The ZWZ was to be purely military; from 1940 political matters belonged to the Government Delegation.

After the fall of France, on 30 June 1940, Rowecki became commander-in-chief and the command moved to occupied Poland. The ZWZ built a network of districts, intelligence and communications, and absorbed smaller organisations. On 14 February 1942 General Sikorski renamed it the Home Army, with no change to its structure.