The correct option is "cruel, heartless"
King Leopold II was the second king of the Belgians. He succeeded his father, Leopold I, on the throne of Belgium in 1865 and remained until his death. He reigned for 44 years, with what became the longest reign of any Belgian monarch so far.
Leopoldo was the founder and sole owner of the Free State of the Congo, a private project headed by himself. He used the explorer Henry Morton Stanley to help him reclaim the Congo, an area currently occupied by the Democratic Republic of the Congo. At the Berlin Conference of 1884-1885, European nations with colonial interests - which agreed to the sharing of Africa - undertook to improve the lives of the native inhabitants of the Congo, while at the same time confirming their possession by Leopold II. However, from the beginning the monarch ignored these conditions and amassed a great fortune thanks to the exploitation of Congo's natural resources - rubber, diamonds and other precious stones - and the use of the native population as forced and slave labor. His African regime was responsible for the death of almost 15 million Congolese. Bertrand Russell estimated the number of victims at 8 million people.