The period of direct colonial rule in Africa was relatively short in duration (1884- 1961); however it had a far-reaching impact on the domestic and international politics of African nation. For example, imposition of the European nation-state system onto the extremely rich and varied African political systems that existed during the pre-slave trade and pre-colonial independence era.  When this system was grafted onto Africa, sovereignty remained in the hands of the occupying colonial powers. The application of this system onto Africa, entailed the sub-division of the entire continent into separate colonies with clearly defined boundaries and centralised political authorities. The boundaries of these colonial political unit became the basis for the contemporary political map of Africa. The imposition of the European nation-state system created a series of artificial states that,  like their counterparts European did. It evolve gradually according to the wishes of local African peoples. European authorities constructed them with little concern for local socio-economic or political-military conditions.  As a result, the artificially created colonial territories more little resemblance to the classic definition of a nation-state, like one people or ethnic group (the nation) ruled by a legitimate centralised authority (the state).  The primaly long-term problem associated with the political division done was the people among many states were the potential emergence of nationalism and the political desire of nationalists to reunite their separated peoples in one unified nation-state.