Answer:
King Leopold advocated for colonial expansion in Africa in the late 19th century before the official scramble for Africa, so he got first dibs on a vulnerable country.
Step-by-step explanation:
King Leopold advocated very strongly for the Belgian government to invest more in colonialism in Africa and because Leopold had a social darwinsim complex which justified imperialism, he was able to gain control by threatening nations such as Congo into signing "agreements" that the leaders in Congo couldn't understand. Hope this helps! Read more into the Scramble for Africa, Social Darwinism and Imperialism if you are still confused!