In the beginning the private army King Leopold had decreed into existence in 1886, the Force Publique, was composed largely of African mercenaries recruited outside the Congo. Of the original 2,000 other ranks of the force, only 111 were Congolese. Preference in early recruiting was given to that much sought after “martial race”, the Hausas of the Central Sudan. In the end, however, these foreign mercenaries proved to be too expensive and local recruiting was intensified. In 1891, chiefs were ordered to produce a certain number of recruits per year, and a militia was founded from which men could be drafted to fill out the ranks in emergencies. In 1900 the term of enlistment in the Force Publique was raised from five to seven years. The Free State also used large numbers of irregulars in its campaigns. The Azande people of the north Congo and the Batetela people, who lived between the Sankuru and the Lomami rivers in the south central area of the Congo, were frequently employed in this capacity. The main attraction was the promise of booty.

Although officials always denied it, there were continual charges that, in order to terrorize its enemies, the Force Publique went out of its way to recruit cannibals. An English visitor to the Congo in the 1890s, E.S. Grogan, described Force Publique recruits as “degraded and vice-sodden cannibals” and charged that their officers expected them to supply themselves with food and clothing through “commandeering” or looting. During the Arab wars of the 1890s, Force Publique officers admitted that there were outbreaks of cannibalism in their forces, but claimed that this was the work of irregulars. Since these mercenaries were not subject to army discipline, wrote the authors of the official history of the Force Publique, “it was impossible to stop them from eating a certain number of victims after each battle”.

The Force Publique increased its numbers tenfold in the first decade of its existence, largely because of the requirements of the Arab wars. By 1898 it boasted nearly 20,000 men (although numbers plummeted thereafter, with the collapse of Leopold’s plans to occupy the southern Sudan). The army maintained a military camp in each of the Free State’s districts. More important were the base camps, where regional headquarters were located and basic training carried out. The most important of these camps were at Eambu Luku, near Boma, and at Irebu and Lisala, in the north around the junction between the Ubangi and Congo rivers. Since the latter region was a major catchment area for recruits, it was no coincidence that the Lingala language spoken there in time became the lingua franca of the army. The greatest challenge faced by the Force Publique in its early years came in the 1890s, in the so-called “Arab wars”.

The sharpest struggles were those that had to be undertaken not against the Africans, but against Swahili slave traders (often called “Arabs” but rarely of pure Arab descent) and their followers in the eastern Congo.