It is a Roman Catholic Church that graces the hill top of Rubaga, previously the site for the Royal Palace of Kabaka Mutesa. The church houses the remains of the first African Catholic Bishop and the first African Archbishop of Kampala Diocese, Joseph Kiwanuka.  The construction  started in 1914 and the Cathedral was completed with donations from Catholics in Uganda and abroad, and was consecrated in 1925. It is said that the blood of the martyrs is the seed of Christianity.

The Cathedral of St. Mary in Rubaga replaced the palace of King Mwanga, which once stood on the same spot.

Sunday the Luganda Masses are at 7.00a.m. and 9.00a.m while English Masses are at 8.00a.m. The General Masses are at 10.00a.m. and at 5.00p.m.