The physical borders of the territory haven’t changed much since 1885, although its political structure has undergone numerous changes, as historian David van Reybrouck wrote in 2010:
In 1885 the region fell into the hands of King Leopold II of Belgium. Leopold named it the Etat Independant du Congo (Independent State of Congo), commonly referred to in the Dutch language as Congo-Vrijstaat. In 1908, in the face of virulent criticism at home and abroad, he transferred his holdings to the Belgian state. It would continue to be called the Belgian Congo until 1960, when it became an independent country, the Republic of Congo. In 1965 Joseph-Desire Mobutu carried out a coup that kept him in power for thirty-two years. During that period, the country received a new name, Zaire. In 1997, when Mobutu was dethroned by Laurent-Desire Kabila, it was renamed the Democratic Republic of the Congo. The “democratic” part required some patience, however, for it was only in 2006 that the first free elections were held in more than forty years. Joseph Kabila, son of Laurent-Desire, was elected president.
The physical boundaries of the territory did “exhibit a striking geographical cohesion,” he notes. They “coincided to a great degree with the drainage basin of the Congo River.”
The river flows through the heart of the DRC and on to the Atlantic: “Each stream, each watercourse empties at some point into that single, powerful river.” So the shape of the country is to some extent natural and organic.
While the land of the DRC exhibits a unity of form, the people do not. The warfare between the various tribes has been nearly constant during some decades. This is one reason for the region’s failure to develop, as historian Tim Marshall explains:
The DRC is an illustration of why the catch-all term 'developing world’ is far too broad-brush a way to describe countries which are not part of the modern industrialized world. The DRC is not developing, nor does it show any signs of so doing. The DRC should never have been put together; it has fallen apart and is the most under-reported war zone in the world, despite the fact that six million people have died there during wars which have been fought since the late 1990s.
The term “developing world” was introduced to replace the category of “third world” in describing various states. But only some “third world” countries develop, while others don’t, so it is a mistake to describe all “third world” countries as “developing” countries.
A big task for historians who write about the twentieth and twenty-first centuries is this: to explain why some countries develop and others don’t. The world has seen clear examples of both paths. What are the cultural, social, and political obstacles to civilization? Which mechanisms exist inside nations to promote or oppose development?