From 1907 to 1908, Adolf Friedrich led a scientific research expedition in the region of the Central African Graben and traversed Africa from east to west. In 1908, he was awarded the Eduard Vogel Medal of the Association of Geography of Leipzig. The insects from his expeditions and residence in Togo are in the Museum für Naturkunde in Berlin and in the Senckenberg Museum From 1910 to 1911, he led an expedition to Lake Chad and the northern rivers of the Congo to the Nile in current Sudan. Adolf Friedrich and his companions explored the then little-known primeval forest region of the Congo tributaries and the basin of Lake Chad. Individual groups extended their explorations to the Bahr el Ghazal near the upper Nile, while others travelled to south Cameroon and the islands of the Gulf of Guinea. Vom Kongo zum Niger und Nil, a two-volume work based on the 1910-1911 expeditions, has an excellent reputation today for its detail and images. From 1912 to 1914, Adolf Friedrich was the last governor of Togoland in German West Africa; he was invited for the official celebration of the independence of Togo in 1960. After World War I, he served as the vice-president of the privately chartered German Colonial Society for Southwest Africa; his brother Johann Albrecht was president from 1895 to 1920.
After Soviet Russia had formally relinquished all authority over its former imperialBaltic provinces to Germany in the Treaty of Brest-Litovsk the Duchy of Courland was nominally recognized as a sovereign state by Kaiser William II on 22 September 1918. A temporary regency council for all the Baltic provinces led by Baron Adolf Pilar von Pilchau was formed on 5 November 1918. It was to be a confederation of seven cantons: Kurland, Riga, Lettgallen, Südlivland, Nordlivland, Ösel, and Estland. The capital of the new state was to be Riga. The proposed United Baltic Duchy was to be located in the future territory of Latvia and Estonia covering the territory of the medieval Livonian Confederation. The first head of state of the United Baltic Duchy was to be Adolf Friedrich, but he never assumed office. The appointed regency council consisting of four Baltic Germans, three Estonians and three Latvians functioned until 28 November 1918, without any international recognition, except from Germany.
Adolf Friedrich is commemorated in the scientific names of a genus of lizards, Adolfus, and of a species of chameleon, Kinyongia adolfifriderici, as well as in the cichlidHaplochromis adolphifrederici.
Works
Ins innerste Afrika. Leipzig, 1909. Translated into English as In the Heart of Africa. London: Cassell, 1910. , , .
Vom Kongo zum Niger und Nil. Leipzig: F.A. Brockhaus, 1912. Translated into English as: From the Congo to the Niger and the Nile: An Account of the German Central African Expedition of 1910-1911. London: Duckworth, 1913. .
Wissenschaftliche Erlebnisse der Deutschen Zentral-Afrika-Expedition unter Führung Adolf Friedrichs, Herzog zu Mecklenburg. Leipzig, 1922. , , , .