There are two countries in Africa with the same name but different capitals:

Congo Republic with the capital Brazzavile and the Democratic Republic of Congo with the capital Kinshasa.

Kinshasa is Africa's third-largest urban area after Cairo and Lagos. It is also the world's largest Francophone urban area (recently surpassing Paris in population), with French being the language of government, schools, newspapers, public services, and high-end commerce in the city, while Lingala is used as a lingua franca in the street.

The city was founded as a trading post by Henry Morton Stanley in 1881. It was named Léopoldville in the honour of King Leopold II of Belgium, who controlled the vast territory that is now the Democratic Republic of the Congo, not as a colony but as a private property. The post flourished as the first navigable port on the Congo River above Livingstone Falls, a series of rapids over 300 kilometres (190 miles) below Leopoldville. At first, all goods arriving by sea or being sent by sea had to be carried by porters between Léopoldville and Matadi, the port below the rapids and 150 km (93 mi) from the coast.

Kinshasa is a city of sharp contrasts, with affluent residential and commercial areas and three universities alongside sprawling slums. It is located along the south bank of the Congo River, downstream on the Pool Malebo and directly opposite the city of Brazzaville, capital of the Republic of the Congo.

The population of Kinshasa is about 9 500 000.

More Info: en.wikipedia.org