One of the few claims that has been verified to some extent is his work to protect the "Prominente", a group of high-ranking or otherwise important POWs that had been held at Colditz Castle until 13 April 1945. There were a total of 21 "Prominente", including Viscount Lascelles and the Master of Elphinstone, both nephews of King George VI, and Giles Romilly, a nephew of the British Prime Minister Winston Churchill. Berger arranged for them to be evacuated from Colditz and transported south and handed over to advancing U.S. Army troops. On 23 August 1944, an uprising broke out against the German puppet government in the Slovak State. The revolt was centred on Banská Bystrica high in the Low Tatra mountains. The rebellion was led by several former members of the Government, and included elements of the Slovak Army and some British-trained parachutists. The uprising was relying on a rapid advance of the Red Army into the Slovak State. Despite the fact that the Soviet armies were just over away at the time the revolt began, they did not reach the rebels in time. On 31 August, Berger was appointed Military Commander in Slovakia, and held sway for the next three weeks. His tasks were to disarm the Slovak Army, ensure lines of communication to the Eastern Front and restore order. He was also to work with the right-wing Hlinka Guard to establish a new armed force in the puppet state. A new Slovak government was established under the leadership of Štefan Tiso. Berger's initial force consisted of several ad hoc "kampfgruppen" (combat groups) totalling 10,000 men, against a rebel army of some 47,000. On 9 September, Himmler advised Berger that he had been awarded the Iron Cross Second Class for his work in Slovakia. By mid-September, the uprising had yet to be quelled, and the only regions that had been pacified were western Slovakia and the Váh valley, although the rebels had been encircled. Due to Berger's lack of success, Himmler replaced him with a HSSPF, Hermann Höfle, and Berger relinquished the role of Military Commander in Slovakia on 19 September. Höfle then bloodily suppressed the revolt with the assistance of additional troops that arrived in late October. Berger was then appointed to organise the "Volkssturm" (Home Guard) in Germany. As Germany's situation deteriorated, Hitler decided to form the "Volkssturm", a Nazi Party local militia to defend communities within the Reich.