In the year 1900 Bishop Streicher, Vicar Apostolic of the Vicariate of North Nyanza, sent two White Father Missionaries (Missionaries of Africa) to South Western Uganda to explore the possibility of introducing Catholicism. These were Fr. Lebros and Bro. Hermann Kock.
The two approached Nkore, the present geographical area which is now Mbarara Archdiocese, through Kooki, in Masaka Diocese. Joseph Rutebemberwa, one of the pioneer catechists led them. A son of that catechist, Msgr. Thomas Bishanga, became the second priest of Mbarara, having been ordained in 1944.
On arrival of the missionaries, Kahaya II, the then King of Karo-Karungi gave Nyamitanga Hill to them to set up their quarters and chapel. This later became the seat and foundation of their mission and is presently the Diocesan Centre of Mbarara Archdiocese.
In 1909, Fr. Borrel opened Rugazi mission, now Rugazi Parish. In the same year, Fathers Letohic and Lefleur opened Rushoroza mission in Kabale, Kigezi. In October 1912, Fathers Bringuier, Nicolet and Bro. Tobie Kizza, the first African Brother to join the White Fathers, opened Ibanda mission. In 1919 Fr. Lefleur founded Kitabi mission.
The Rwenzori Vicariate
Rwenzori Vicariate was carved out of the Vicariate of Uganda on 28th March 1934. The new Ecclesiastical territory then covered the political districts of Western Uganda, i.e. Nkore, Kigezi, Toro and Bunyoro.
On July 25 1934, Fr. Francis-Xavier Lacoursiere of the White Fathers was ordained first Bishop of Rwenzori Vicariate. Nyamitanga in Mbarara became the seat of the Vicariate. The size of the Vicariate was 400 square miles with 13 missions.