After the armistice of 1943, the city became a key centre of the Italian resistance movement. On 7 November 1944, a pitched battle around Porta Lame, waged by partisans of the 7th Brigade of the "Gruppi d'Azione Patriottica" against Fascist and Nazi occupation forces, did not succeed in triggering a general uprising, despite being one of the largest resistance-led urban conflicts in the European theatre. Resistance forces entered Bologna on the morning of 21 April 1945. By this time, the Germans had already largely left the city in the face of the Allied advance, spearheaded by Polish forces advancing from the east during the Battle of Bologna which had been fought since 9 April. First to arrive in the centre was the 87th Infantry Regiment of the Friuli Combat Group under general Arturo Scattini, who entered the centre from "Porta Maggiore" to the south. Since the soldiers were dressed in British outfits, they were initially thought to be part of the allied forces; when the local inhabitants heard the soldiers were speaking Italian, they poured out onto the streets to celebrate.