Final answer:
Belgium imperialized the Congo under King Leopold II through deceit at the Berlin Conference, claiming to promote free trade and humanitarian goals while, in reality, brutally exploiting the region's resources and labor. European powers spread imperialism swiftly due to technological superiority and strategic diplomacy.
Step-by-step explanation:
Belgium was able to imperialize the Congo under the rule of King Leopold II, who sought to establish an empire despite Belgium being one of the smaller industrialized nations. Leopold II set up the International African Association in 1876, falsely claiming his intentions were humanitarian. At the Berlin Conference in 1884, he secured control over the Congo by promising a free-trade zone and the well-being of the Congolese people. However, this was a front for exploitation and brutality, as the Congo Free State became an area where Europeans could exploit African laborers for profit, especially for resources such as ivory and rubber.