Soon, however, the missionaries had to abandon Omach, on the Eastern bank of the Victoria Nile, because of sleeping sickness. The mission post was moved to Gulu. New mission stations were opened from there during the following years: in Madi (1917), Lango (1930) and Karamoja (1933). In 1923 Gulu was erected as a separate Apostolic Prefecture under Fr. Antonio Vignato. In 1938 Bishop Angelo Negri, Bignator's successor, ordained the first two priests of the growing Vicariate.
From the very beginning, education was one of the primary concerns of the Comboni Missionaries. Brothers were mostly engaged in farm and trade schools, while the Comboni Sisters gave their contribution in establishing and running girls' schools and convents for indigenous vocations. The development of these schools reached its peak during the fifties and early sixties.
The Comboni Missionaries also founded some of the Uganda's finest hospitals, like Lachor (in Gulu), St. Joseph's Kitgum and Kalongo. Lachor and Kalongo have nursing and midwifery schools attached. They are still offering quality medical care to a population that has been seriously tried by two decades of war in Acholiland.
With the approach of independence, the Comboni Missionaries played a leading role in enlightening the people on the Christian teaching on social and political affairs. This was done mostly through the activities of the Catholic Action, the foundation of Leadership magazine and the Gulu Catholic Press.
Following the nationalisation of the schools in 1964 the Comboni Missionaries, now free of many of the responsibilities of teaching and school administration, were able to plunge more deeply into pastoral work. Both during the time of Obote (1960s) and of Idi Amin (1970s) a number of Comboni Missionaries were expelled from Uganda.