He was born at Nakawa in 1868. His father was Muteesa I of Buganda, who reigned between 1856 and 1884. His mother was Abakyala Abisagi Bagalayaze, the tenth wife of his father's eighty five wives. He ascended to the throne on October 18, 1884, after the death of his father. He established his capital on Mengo Hill.
Mwanga came to the throne at the age of 16. He increasingly regarded the greatest threat to his rule coming from the Christian missionaries who had gradually penetrated Buganda. His father had played-off the three religions, Catholics, Protestants and Muslims, against each other and thus balanced the influence of the European colonial powers that were backing each group in order to extend their reach into Africa. Mwanga II took a much more aggressive approach, expelling missionaries and insisting that Christian converts abandon their faith or face death. A year after becoming king he executed Yusufu Rugarama, Makko Kakumba, and Nuuwa Sserwanga, who had converted to Christianity. On October 29, 1885, he had the incoming archbishop James Hannington assassinated on the eastern border of his kingdom.
For Mwanga, the ultimate humiliation was the insolence he received from the (male) pages of his harem when they resisted his sexual advances. According to old tradition the king was the center of power and authority, and he could dispense with any life as he felt. It was unheard of for mere pages to reject the wishes of a king. Given those conflicting values Mwanga was determined to rid his kingdom of the new teaching and its followers. Mwanga therefore precipitated a showdown in May 1886 by ordering converts in his court to choose between their new faith and complete obedience to his orders and kingdom.
It is believed that at least thirty Catholic and Protestant neophytes went to their deaths. Twenty-two of the men, who had converted to Catholicism, were burned alive at Namugongo in 1886 and later became known as the Uganda Martyrs. Among those executed were two Christians who held the court position of Master of the Pages, Joseph Mukasa Balikuddembe and Charles Lwanga. They had repeatedly defied the king by rescuing royal pages in their care from sexual exploitation by Mwanga which they believed contrary to Christian teaching
These murders and Mwanga's continued resistance alarmed the British, who backed a rebellion by Christian and Muslim groups who supported Mwanga's half brother and defeated Mwanga at Mengo in 1888. Mwanga's brother, Kiweewa Nnyonyintono, was elevated to the throne. He lasted exactly one month and was replaced on the throne by another brother, Kabaka Kalema Muguluma. However, Mwanga escaped and negotiated with the British. In exchange for handing over some of his sovereignty to the British East Africa Company, the British changed their backing to Mwanga, who swiftly removed Kalema from the throne in 1889.
On 26 December 1890, Mwanga signed a treaty with Lord Lugard, granting certain powers over revenue, trade and the administration of justice to the Imperial British East Africa Company. These powers were transferred to the crown on 1 April 1893.
On 27 August 1894, Mwanga accepted for Buganda to become a Protectorate. However, on 6 July 1897 he declared war on the British and launched an attack but was defeated on 20 July 1897, in Buddu (in today's Masaka District). He fled into German East Africa (today it is Tanzania), where he was arrested and interned at Bukoba.
He was deposed in absentia on 9 August 1897. Tenacious as he was, he escaped and returned to Buganda with a rebel army, but was again defeated on 15 January 1898. He was captured and in April 1899 was exiled to the Seychelles. While in exile, he was received into the Anglican Church and was baptized with the name of Danieri (Daniel). He spent the rest of his life in exile. He died in 1903 at the age of 34 or 35. In 1910, his remains were repatriated and buried at Kasubi.
He is on record as having married sixteen wives:
- Damali Bayita Nanjobe
- Naabakyaala Dolosi Mwaan'omu Bakazikubawa
- Esiteri Nabunnya
- Naabakyaala Eveliini Kulabako, Omubikka
- Naabakyaala Loyiroosa Nakibuuka, Kaddulubaale
- Naabakyaala Samali Namuwanga, Sabaddu
- Nakijoba Nabulya (Elizabeeti Oliva Kyebuzibwa born of Mwanje Bikaali)
- Bezza Batwegombya
- Naabakyaala Ntongo, Kabejja
- Naabakyaala Nabisubi, Omuwanga
- Lakeeri Mbekeka
- Nalwooga, Omuyigiriza
- Elizaabeeti Buteba
- Nattimba Binti Juma
Mwanga II fathered seven sons and three daughters including Daudi Chwa II of Buganda:
Photo of Portrait of Mwanga II on Flickr.com
- Prince (Omulangira) Kagolo, whose mother was Damali Bayita Nanjobe. He was killed by his uncle Kalema, in 1889.
- Prince (Omulangira) Mulindwa, whose mother was Nabweteme
- Prince (Omulangira) Nganda, whose mother was Lakeeri Mbekeka
- Daudi Chwa II of Buganda, who reigned from 1897 until 1939. His mother was Eveliini Kulabako.
- Prince (Omulangira) Yusuufu Suuna Kiweewa, whose mother was Esiteri Nabunnya. He was born at Mengo, Uganda on 16 February 1898 and was educated at Mengo High School and King's College Budo. Commissioned 2nd Lieutenant on October 1914. He served in the Great War from 1915 until 1919. Promoted to Lieutenant in the 7th Territorial Battalion on the 25th May 1939. He served in the Second World War in Eastern Africa and in North Africa, from 1939 until 1940. Retired on the 18th March 1940. He was implicated in the Buganda riots of 1949 and exiled to the Ssese Islands, where he died in 1949.
- Prince (Omulangira) Tobi, whose mother was Nabisubi
- Prince (Omulangira) Nayime?, whose mother was Loyiroosa Nakibuuka
- Princess (Omumbejja) Najjuma Katebe, whose mother is not mentioned
- Princess (Omumbejja) Anna Nambi Nassolo, whose mother was Samali Namuwanga
- Princess (Omumbejja) Mboni Maliamu Kajja-Obunaku, whose mother was Nattimba. She was educated at Saint Monica's School in Zanzibar.