In 1939 Dollmann was appointed German Ambassador to the Holy See. He helped Virginia Agnelli escape from detention and was with her help able to arrange a meeting between SS-Obergruppenführer Karl Wolff and Pope Pius XII to negotiate the peaceful German evacuation of Rome. Later, as Befehlshaber der Polizei, he was Adjutant of Karl Wolff in a villa on the Lake Garda. On 20 July 1944 Dollmann was official interpreter at the meeting of Adolf Hitler and Benito Mussolini, at the Wolfsschanze, immediately after the 20 July plot.