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.

[4] 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.

He was concerned at the growing influence of Christianity and the rise of a new class of officials, distinct from the traditional territorial chiefs, who were educated, had a religious orientation, and wished to reform Ganda society.

[3] Encouraged by his prime minister, on 29 October 1885 he had the incoming Anglican bishop James Hannington assassinated on the eastern border of his kingdom.

Those killed included minor chiefs, some of whom, such as Joseph Mukasa, were "the victims of particular grudges by their seniors ... jealous that these up and coming young men would soon be ousting them from power".

[12] A witness to the event, the French missionary priest Lourdel, considered that the principal cause was Mwanga's feeling of being despised by the literate Christians who claimed a superior knowledge of religion.

Lourdel gave as a secondary cause of Mwanga's action the refusal of the pages to meet traditional royal demands of sexual submission.

"[23] In the week leading to the executions, the Christian Matthias Gayinga rejected the sexual demands of Mwanga's close friend, the Muslim Lutaya, to whom the king had sent him for that purpose.

His action was followed by the refusal of another convert, Anatole Kirrigwajjo, to accept nomination to a high post "which he could only exercise at the peril of his soul".

Mwanga saw this as an attempt "to rob him of his favourite and so far always compliant toy, by teaching him the religion which made them prefer death to submission".

By displaying the courage their Christianity demanded, they helped remove any notion that the new religion was inconsistent with traditional ideals of heroism.

[26][27] The same description appeared also, of course, in religious publications, both Protestant, such as the journal of the missionary Mackay published in the Intellegencer of 1886,[28] and Catholic, such as the accounts of the missionaries Lourdel, Denoit, and Delmas published in Enquête relative au martyre des chrétiens: Ste Marie de Rubaga, Buganda 1888 and Les Missions Catholiques 18 (1886).

The Times of 30 October 1886, quoting the dictum, "the blood of martyrs is the seed of the Church", stated: "On the success of the Uganda experiment, with its alternation of favourable and adverse circumstances, depends the happiness of the interior of the vast continent for generations.

[29] In September 1888, Mwanga planned to get rid of remaining Christian and Muslim leaders by leaving them to starve on an island in crocodile-infested Lake Victoria.

In October 1888, the Muslims seized power, expelled the Christian leaders and, when Kiweewa refused to be circumcised, deposed and killed him, replacing him with another brother, Kalema.

He was defeated, but the Christian forces, led by the Protestant chief Apollo Kaggwa, retook the capital, enabling Mwanga to enter it triumphantly on 11 October 1889.

[31] The agreement that Peters made with Mwanga was nullified by the 1 July 1890 treaty between Britain and Germany, which extended inland the line of division between their areas of influence in East Africa, leaving Buganda in the British sphere and moving the centre of interest from the coast to the hinterland.

Lugard managed to persuade Mwanga to return from German territory, where he had taken refuge, to Mengo on 30 March 1892 and to make a new treaty.

Defeated on 20 July in Buddu (in today's Masaka District), an area assigned to Catholics in the 1892 treaty, he again fled to German East Africa.

[34] According to Heike Behrend, following the deaths, the Roman Catholic Church used the episode to make the victims the focus of a "cult of martyrs".

Official groundbreaking was on 3 May 2015 by the Papal Nuncio to Uganda, Archbishop Michael A. Blume, and Cardinal Emmanuel Wamala.

[7] The hymns and songs that were composed about the Uganda marytrs include; The Ugandan Martyrs were featured in one episode of the film Millions.