Frederik-Valdemar Olsen (24 May 1877 – 19 November 1962) was a Danish soldier who became a general and commander in chief of the Belgian Congo Force Publique.He was born into a poor family, joined the Danish army, then in 1898 volunteered to serve in the Congo Free State.He rose quickly through the ranks, and in 1909–1910 played an important role in a stand-off with German and British forces disputing the eastern border of what was now the Belgian Congo.During World War I Olsen commanded a force that defended Northern Rhodesia against a German attack, then advanced from the south of Lake Kivu to take Tabora in what is now Tanzania.After the war he became commander of the Force Publique before retiring as a general in 1925. Olsen was then made general manager of the state-owned Congo River