Werner von Rheinbaben (1878-1975) came from one of the leading families of Wilhelmine Germany. After a rapid career in the Imperial Navy, he entered the diplomatic service in 1912. As secretary of the German legation in Brussels, he delivered the ultimatum to the Belgian government in August 1914, marking the beginning of World War I in the West. The collapse of the monarchy prompted Rheinbaben to become a professional politician in 1919: as a foreign policy expert for the German People's Party (DVP) and the right-hand man of its chairman and long-serving German Foreign Minister Gustav Stresemann, he drafted the foreign policy platform of his party. From 1920 to 1930, he served as a member of the Reichstag, became head of the Reich Chancellery in 1923, later served as Germany's deputy at the League of Nations, and finally led the German delegation at the International.