His father had reached the rank of sergeant major in the engineer corps before retiring and joining the Belgian and French railways.

[1] Delcommune travelled from Luanda to Ambriz where he joined the French merchant Lasnier-Daumas, Lartigue et Cie. At that time he was one of just sixteen Europeans living in the Congo, and the only Belgian.

This involved exploring the whole navigable part of the Congo basin, determining what types and quantities of merchandise could be expected, and assessing whether this would justify the investment.

[1] For this mission he organized the transport of the components of the steamer Le Roi des Belges overland to Leopoldville, where the boat was assembled.

[1] His ascent of the Lomani, which he found to be easy to navigate, took seventeen days and covered over 570 miles (920 km) to around latitude 4° South.

[2] The "Compagnie du Katanga" formed for the expedition was theoretically a private organization, but in practice was an instrument of the Congo Free State.

With Delcommune were the geologist Diderrich, the naturalist Protche, doctor Briard, Baron de Roest d'Alkemade and Count Soutchoff.

[8][fn 1] In Katanga, the Nyamwezi trader Msiri had seized power around 1860, expanding his empire to cover a large part of the Luapula valley.

By the time of Delcommune's expedition his rule had greatly contracted, but both the Belgians in the free State and the British in Southern Africa were determined to fully control the mineral-rich area of Katanga.

A small force of Belgians from an expedition led by Paul Le Marinel had been allowed to establish a post near to Msiri's capital early in 1891.

[12] Delcommune's expedition reached Bunkeya in October 1891, but he was unable to persuade Msiri to accept Belgian rule and continued south.

[13] At the age of 25 the Canadian-born engineer, soldier and mercenary William Grant Stairs had been second in command of Henry Morton Stanley's 1887 expedition to relieve Emin Pasha in Equatoria.

A Belgian steamer on Lake Tanganyika that fought against the forces of German East Africa during the First World War was named the Alexandre Del Commune.

[16] His name was given to the artificial Lake Delcommune, near Kolwezi, formed by a dam across the Lualaba to provide hydroelectric power and a water supply to the copper mining operations.