He ascended to the throne after the death of his uncle, Kabaka Mawanda Sebanakitta, in 1740.
[citation needed] Mwanga I and his brothers were the first Buganda Monarchs to go to Nnagalabi (later to be named Budo) for their coronation ceremonies.
Previous Kabakas had gone to Nankere for the final and most important confirmation ceremony.
Some of the great officers of state during his reign included;[1] He is recorded to have married five (5) wives:[2] He is recorded to have fathered three (3) sons: Mwanga is said to have reigned for only two months; he was a cruel man and it was his cruelty which resulted in his untimely death.
Kabaka Mwanga I Sebanakitta was killed by Nkunnumbi, in revenge for the murder of his son, around 1741.