[2] In 1885 Paul Le Marinel was seconded to the Military Cartographic Institute and was sent to the Congo where he was assigned to the topographical brigade led by Captain Jungers.
Soon after arriving he was transferred to Luluabourg, the administrative capital of the Kasai district, which had been founded a year earlier by the German explorer Hermann Wissmann.
Wissmann went on an expedition to the Lubi, leaving Le Marinel in command of the post, but was soon forced to return due to hostile natives and a smallpox epidemic.
Wissmann decided to press on with a caravan of sixty of the best troops, leaving Le Marinel to return to Luluaberg with the much weakened remainder of the expedition.
While in Boma in April 1888 waiting to embark, he met Alexandre Delcommune, who had a commission from Albert Thys, assistant to King Leopold II of Belgium and founder of the Congo Compagnie de Commerce et d'Industrie.
Arab or Swahili traders had penetrated to the Great Lakes from the east coast of Africa, and were pressing into the Congo Basin in search of slaves and ivory.
The Governor-General, Camille Smith, asked Le Marinel to investigate Bena Kamba, a town on the Lomami, as an alternative place for the post.
[1] Le Marinel brought the Zappo Zaps to Luluabourg, where they were used to enforce the government's policy of taxation and forced labor in the Kasai, earning a reputation for great brutality.
[1] Le Marinel left Lusambo on 23 December 1890 with instructions to raise the Belgian flag in Bunkeya, the Katangan capital, 1,300 kilometres (810 mi) distant.
[6] In January 1891 the group reached Luaba, where they asked permission to cross the Kanyok state controlled by Kabw Muzemb, a well-armed slaver.
[5] In April 1892, Le Marinel handed over command of the fortified post of Lusambo and the Kasai/Lualaba region to Francis Dhanis, and returned to Belgium.
In 1894 he was commissioned to undertake an inspection trip to the Uélé River near the northern border of the Free State which was disputed with the French, and to make comprehensive reforms in the administration.
He received many offers from trading companies to assist in their enterprises in Central Africa, but did not return there until 1906, in the capacity of a director of the Compagnie du Lomami.