Back in Bucharest, in 1908, Marthe was introduced to the German Kronprinz, Wilhelm. Wilhelm (who, despite Marthe's references to him as " the III", was never to succeed Wilhelm II) was married, but he nevertheless wrote warmly affectionate letters to Marthe for the following fifteen years. She and her husband were invited to Germany, in the autumn of the same year, as Wilhelm's personal guests, visiting Berlin, Potsdam, Weimar, and taking part in the imperial regatta at Kiel. Marthe was awarded the supreme honour of accompanying Wilhelm in the imperial limousine, as it passed through the Brandenburg Gate, an entitlement otherwise reserved to members of the imperial family. He would also try to involve Marthe in the international relations of pre-war Europe, secretly asking her to be the quiet mediator between France and Germany on the Alsace-Lorraine issue.