Joseph Mukasa was one of the Uganda Martyrs; a group of 22 Catholic and 23 Anglican converts to Christianity in the historical kingdom of Buganda, now part of Uganda, who were executed between 31 January 1885 and 27 January 1887. Very little is known about the individual martyrs.
They were killed on orders of Mwanga II, the Kabaka (King) of Buganda. The deaths took place at a time when there was a three-way religious struggle for political influence at the Buganda royal court. The episode also occurred against the backdrop of the "Scramble for Africa" – the invasion, occupation, division, colonization and annexation of African territory by European powers. A few years after, the English Church Missionary Society used the deaths to enlist wider public support for the British acquisition of Uganda for the Empire. The Catholic Church beatified the 22 Catholic martyrs of its faith in 1920 and canonized them in 1964.