Claim: Leopold II of Belgium was king of Belgium from 1865 to 1909.

Leopold II -LRB- 9 April 1835 -- 17 December 1909 -RRB- reigned as the second King of the Belgians from 1865 to 1909 . He became known for the founding and exploitation of the Congo Free State as a private venture . Born in Brussels as the second -LRB- but eldest surviving -RRB- son of Leopold I and Louise of Orléans ,  he succeeded his father to the Belgian throne in 1865 and reigned for 44 years until his death - the longest reign of any Belgian monarch . He died without surviving male issue ; the current Belgian king descends from his nephew and successor , Albert I.   Leopold became the founder and sole owner of the Congo Free State , a private project undertaken on his own behalf . He used explorer Henry Morton Stanley to help him lay claim to the Congo , the present-day Democratic Republic of the Congo . At the Berlin Conference of 1884 -- 1885 the colonial nations of Europe authorized his claim by committing the Congo Free State to improving the lives of the native inhabitants . From the beginning , however , Leopold essentially ignored these conditions . He ran the Congo using the mercenary Force Publique for his personal enrichment . He used great sums of the money from this exploitation for public and private construction projects in Belgium during this period . He donated the private buildings to the state before his death , to preserve them for Belgium .   Leopold extracted a fortune from the Congo , initially by the collection of ivory , and - after a rise in the price of rubber in the 1890s - by forced labour from the natives to harvest and process rubber . Under his régime millions of the Congolese people died ; modern estimates range from 1 to 15 million , with a consensus growing around 10 million . Human-rights abuses under his régime contributed significantly to these deaths . Reports of deaths and abuse led to a major international scandal in the early 20th century , and the Belgian government ultimately forced Leopold to relinquish control of the colony to Belgian civil administration in 1908 .