Beginning around the 1700s, under the development of technology in many aspects, the Europeans started their expedition to explore the world. After the discover of many unknown lands, they soon developed a policy to extend their power and influence through colonies, with violence and blood. The policy was known as "imperialism ". In Africa, European imperialists ruled, killed, enslaved, and traded millions of native Africans like merchandise while also robbing all the approachable natural resources. Imperialists apparently brought a catastrophe into Africa while they even caused a lot of leftover problems to the modern Africa. However, back to the 1800s, imperialists did not think imperialism was a fault. With better-developed technology, Europeans started to believe that they enjoyed superiority in all aspects, including economics, culture and race. They made up many justifications to defend their crimes that related to these three aspects. Most of the justification could be categorized into two camps: the "internal camp " and the "external camp ". In the "internal camp ", imperialists justified themselves by connecting "nationalism " and "imperialism ", which they believed ruling an "inferior race " was an efficient way to enrich their home countries. One of the related theories was "Social Darwinism ". The "external camp " believed the intention of imperialism was to help and benefit the "barbaric " natives. One of the popular theories was the "duty theory ". However, activist Roger Casement heavily criticized imperialism by using the same concepts. He disproved both camps by pointing that imperialism neither necessarily enriched nations nor brought any benefit to the natives. With his documentary report on the Congo Free State, which was privately controlled by King Leopold II of Belgium, we could observe the unreliability of those justifications. .
Many of the popular justification could be categorized into the "internal camp ", which believed their deeds were intended to benefit their home countries.
