[1][2] He was born at Kalmthout on 21 August 1850, the son of Guillaume-Joseph Becker and Anne-Marie Anthonissen, and joined the 5th Artillery Regiment before being seconded to the Military Cartography Institute.

In this capacity, he was first sent to Central Africa under Jules Ramaeckers in 1880, travelling to Karema, where he participated in the development and "beautification" of the town, and befriended both Mirambo and Tippu Tib.

[3] In 1884, Becker was ordered to lead an expedition to Lake Tanganyika, to link a series of captured bomas with forts he would build further inland.

Due to his pro-Zanzibari Arab sympathies, in 1889, he was sent to the Stanley Falls District of the Congo Free State to try and re-establish good relations with Tippu Tib and his Arabs, who held de facto power in the region and had been made a salaried employee of the Free State two years previously.

Although he failed to make any lasting contracts with Tippu Tib,[5] he did acquire much ivory from him,[6] and taught his son Sefu bin Hamid to write Swahili in Latin script.