Karegyesa was born on September 23, 1924 in Misheruro village, Rukingiri district. This was near the current district headquarters.
He was born to Rujumubura chief Edward Suleman Karegyesa and Esteri Kwasherura Bureeba from the Bakimbiri clan.
Karegyesa was the last born of 17 children.
Karegyesa attended Kinyasano Elementary Primary School, before joining Kigezi High School for his secondary school education. Among the people he studied with here was Justus Byagagaire.
He also attended Mbarara High School with the likes of Hezron Kakuyo, Bishop Ruhindi, Tom Kayangire, Norman Kachesereza and Elias Biryabarema.
His secondary school studies also saw him through Mwiri College School in Busoga with then-future president Milton Obote.
Later, Karegyesa attended Entebbe Veterinary Institute for a veterinary officer’s course, before furthering his experience in that field in neighouring Kenya. There, he went to Kabete Veterinary Training Institute in the capital Nairobi for higher training.
After there, Karegyesa flew to the United Kingdom for further training in veterinary practice.
At the age of 30, Karegyesa married Deborah Muhumuza, the daughter of Canon and Buningwire MBE, a renowned evangelist.
His best man at the 1950 wedding Nassan Ruyondo, the father of Kwame Ruyondo.
The couple had eight children together: four boys and four girls. One of them, Topher, passed away in 1987.
After completing his studies, Karegyesa was posted as a veterinary officer in Bwongyera, Kajara district of Ankole, where he served until 1959.
He then joined the Legislative Council (LEGCO) in pre-independent Uganda.
One year before Uganda's independence, Karegyesa joined active party politics and ran under the Uganda Peoples’ Congress (UPC) ticket.
His challenger, a one Katungwesi of the Democratic Party (DP), was the headmaster of Nyakabare Primary School. But he was no match for the political newcomer. Karegyesa convincingly defeated him by a huge margin.
In 1962, he went to Parliament and was appointed deputy minister of animal industry, game and fisheries. He deputised John Babiiha, the vice-president at the time. Effectively, Karegyesa was in charge of the ministry.
Achievements and milestones (1961- 1971)
Here are some of Karegyesa's highlights in that period of time:
• Started Nationwide agitation for Independence and Self governance with other luminaries like Ibingira, Kangaho, Obwangor, Byanyima and Milton Obote.
• Fully set up the Ministry of Animal, Industry, Game and Fisheries
• Establishment of Soroti Meat Packers
• Oversaw establishment of TUFMAC
• Gave a head start to Cooperative Movement
• Spearheaded establishment of Ranching Scheme in Uganda
• Establishment of Wildlife Department
• Introduction of Exotic cattle for breeding
• He strongly discouraged nomadism
• Introduction of wooden fencing and modern farming methods
• Establishment of enforcement of extension Workers Programme
• Establishment of Uganda Dairy Corporation
• Constructon of valley dams in the Cattle Corridor
• Establishment of spray races and dip tanks for tick control
• Eradication of tsetse flies and ticks
• Introduction of Coffee and Cotton in Kigezi North
• Establishment of Nyakibare, Kisiizi and Kambuga Hospitals
• Tobacco factory was also established during his leadership
• Building and upgrading of schools in the region – Kigezi High School, Makobore High School and Kinyasano Secondary School
Return to Parliament
In 1980, Karegyesa stood on the UPC ticket in Rujumbura and emerged victor, effectively marking his return to the House as MP.
He also had other roles. He was a member of the Commonwealth Parliamentary Association
Karegyesa was the governor of the Milton Obote Foundation as well as a board member of the Uganda Posts & Telecoms.
In 1986, he retired to commercial ranching and dairy farming in Rukungiri and Nyabushozi. He has been doing that until the time of his death.