A resistance movement soon emerged. On 22 June 1941, the 1st Sisak Partisan Detachment was formed near Sisak, the first military unit formed by a resistance movement in occupied Europe. That sparked the beginning of the Yugoslav Partisan movement, a communist multi-ethnic anti-fascist resistance group led by Josip Broz Tito. The movement grew fast, and at the Tehran Conference in December 1943, the Partisans gained recognition from the Allies.