The Polish resistance movement in World War II, with the Polish Home Army at its forefront, was one of the largest underground resistances 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 anti-fascist resistance movement. It is most notable for disrupting German supply lines to the Eastern Front, providing military intelligence to the British, and for saving more Jewish lives in the Holocaust than any other Allied organization or government. It was a part of the Polish Underground State.