The evaluation of the position of the Catholic missions in the colonial setting of the last quarter of the 19th century and the first quarter of the 20th century runs along two axes of research: the specific position of the mission within the frame of the colonial institutions on the one hand, and the impact on and by the local population(s) on the other hand. The inquiry starts with the first signs of the Congo-ambition of the Belgian King Leopold ii in 1876 and the arrival of the Missionaries of Africa/White Fathers in 1880 on the territory of what was going to officially become the Independent State of the Congo / the Congo Free State five years later. It ends at about the mid-twenties of the 20th century when the most visible period of a tied alliance between mission and state took form and when the time was ready for the first determination of a general ‘politique indigène’ and a concerted missionary strategy towards the local cultures. Apostolic Vicar of Upper-Congo Mgr. Victor Roelens (1858-1947), member of the Society of Missionaries of Africa, was in that period from 1895 on (to 1941) one of the most dominant mission-leaders in the Congo.