France had conquered most of northern Algeria during the period 1830-47, incorporating it as an integral part of France. The 1880s saw an intense competition between the European powers for territories in Africa, a process known as the Scramble for Africa. This culminated in the Berlin Conference of 1884, in which the European nations concerned agreed upon their respective territorial claims and the rules of engagements going forward. As a result of this France gained control the upper valley of the Niger River (roughly equivalent to the areas of modern Mali and Niger). France occupied this area in 1900, followed by Mauritania in 1903-4; these areas later became constituents of the federal colony of French West Africa ("Afrique occidentale française", abbreviated AOF). In the meantime the French had been pushing south from the Algerian littoral, conquering much of the Algerian Sahara in 1902. A boundary between French West Africa and French Algeria (i.e. Algeria’s modern borders with Mauritania, Mali and Niger) was agreed upon 7 June 1905 by the Commandant of Upper Senegal and Niger and the Military Commander of the Department de l'Oasis within French Algeria. The border was further defined by the Niamey Convention of June 1909.