St. Matthias Mulumba Kalemba was a Musoga by tribe from Bunya county in Busoga. His biological parents, however, are not known. But his adopted father was; Magatto of Edible or Cane Rat Clan (Musu).
Mulumba was the oldest of all the martyrs because by the time of his martyrdom he was about 50 years old. He was assistant to county chief of Ssingo called Mukwenda. He was baptized on 28 May 1882 by Pere Girault. Mulumba died the most brutal and longest lingering death of about 3 days (from the afternoon of Thursday 27th to Sunday 30th May 1886). His limbs were cut off from his body, strips of flesh were cut from his back and left to die at Old Kampala. The church built at the place where St. Matia Mulumba was killed.