Africa is geographically divided up into over 50 countries due to centuries of colonial rule, and because of different post-war deals made by other interests, most notably at the end of both World Wars. Therefore there is no country which towers above the rest, size-wise, but Sudan does manage to take the biggest country title, just ahead of Algeria and the democratic Republic of Congo, although if the Congo was united that would assume Africa's largest country mantle. Along with being the top dog in Africa, Sudan is also the largest Arab country globally, and the tenth largest nation in the World overall, but it is almost always in turmoil with different factions set against each other, as we have all witnessed from the images coming out of Darfur. It is bordered by Central African Republic, Chad, the Democratic Republic of the Congo, Egypt, Eritrea, Ethiopia, Kenya, Libya and Uganda, and it is served by the longest river system in the World. The Nile flows right through the entire length of the country, with it's two main tributaries, the White Nile and the Blue Nile, joining up close to the Sudanese capital, Khartoum.