Caracciolo was still in command of the Fifth Army when the Armistice of Cassibile was announced on 8 September 1943. He tried to organize a resistance against German attacks during Operation Achse, but his army gradually disintegrated as several of his subodinates, such as the garrison commanders in Florence, Massa and Arezzo, handed over their cities to the Germans without resistance. On 12 September Caracciolo, who had been personally involved in the fighting, formally dissolved his Army and then went into hiding in Rome, where he made contact with the Fronte Militare Clandestino, a Resistance network composed of former Army officers. The Germans placed a bounty of 20,000 lire on his head, and in January 1944 he was arrested by the Special Police Detachment of Pietro Koch, handed over to the SS, and imprisoned in Verona, Venice and Brescia, where he was tried by the Italian Social Republic’s Special Tribunal and sentenced to death. The sentence was however reduced to a fifteen-year prison term as Caracciolo was a war invalid. He was liberated by the partisans on 25 April 1945.