The organizations forming the Polish Underground State that functioned in Poland throughout the war were loyal to and formally under the Polish government-in-exile, acting through its Government Delegation for Poland. During World War II, hundreds of thousands of Poles joined the underground Polish Home Army ("Armia Krajowa"), a part of the Polish Armed Forces of the government-in-exile. About 200,000 Poles fought on the Western Front in the Polish Armed Forces in the West loyal to the government-in-exile, and about 300,000 in the under the Soviet command on the Eastern Front. The pro-Soviet resistance movement in Poland, led by the Polish Workers' Party, was active from 1941. It was opposed by the gradually forming extreme nationalistic National Armed Forces.