On 17 June 1942, Marseille claimed his 100th aerial victory. He was the 11th Luftwaffe pilot to achieve the century mark. Marseille then returned to Germany for two months leave and the following day was awarded the Knight's Cross of the Iron Cross with Oak Leaves and Swords. On 6 August, he began his journey back to North Africa accompanied by his fiancée Hanne-Lies Küpper. On 13 August, he met Benito Mussolini in Rome and was presented with the highest Italian military award for bravery, the Gold Medal of Military Valor (). While in Italy Marseille disappeared for some time prompting the German authorities to compile a missing persons report, submitted by the "Gestapo" head in Rome, Herbert Kappler. He was finally located. According to rumours he had run off with an Italian girl and was eventually persuaded to return to his unit. Unusually, nothing was ever said about the incident and no repercussions were visited upon Marseille for this indiscretion.