Before Imperialism took rise in the Congo, African society was comprised of different ethnic groups defined by geographical borders. As a result, Europe gradually sought its way into the Congo and economic prosperity grew due to raw material exports, but the treatment of people and the social barriers between the Congolese continued to be strained. Life in Pre-Colonial Congo consisted of free, non-literate societies that used sophisticated tools and also traded with other places. Many clans and kinship groups were ruled by a chief which were formed in small villages. Soon, Europeans began to control parts of Africa and exported their raw materials in act to surpass their neighboring countries. Many leaders expressed their interest for Africa and at one point was called the Scramble for Africa. A leader named King Leopold took control of Central Africa, the Congo Free State, and was a main point in African imperialism and colonialism. In addition, many horrific events took place there and the responses was key to development of Africa and their human rights today. The first people to live in Central Africa were known as "hunter-gatherers" because they lived off the land by collecting fruits and nuts and killing the animals. Small groups called the Bantues from West Africa migrated into Central and Eastern Africa bringing with them the knowledge of melting iron which allowed for sophisticated tools. Another group called the Nilotes migrated into Central Africa and brought with them the techniques of fishing and farming. The techniques introduced by various groups led for Central Africa to flourish agriculturally. Eventually, these groups developed their own distinct languages, social structure, and tribes. This led to the two hundred different ethnic groups in Central Africa, each with its own beliefs and customs. By the 15th and 16th centuries, many empires began to grow as the population increased and began to set up trading networks with countries nearby. As the Imperial Revolution gained more popularity in Europe, Europeans realized that in order to surpass their neighboring countries they need raw materials to fuel their factories as well as people to work. By 1873, Europe faced economic struggles and looked for Africa to supply their needs for a couple of reasons such as competition and religion. Europeans pushed to "be ahead of the game" so a race began among European countries to acquire more knowledge abo