Zachary Theodore Onyonka was born on June 28, 1939, in Meru, where his father, Godrico Oeri Mairura, was a policeman. Zachary was the second child of Oeri and Kerobina Kebati. The family left for Kisii after his father resigned from the police force to join the Provincial Administration as an assistant chief.
In school, Onyonka was brilliant and disciplined. He attended Catholic schools — St Mary’s Nyabururu in 1949 and St Mary’s Yala, where he studied till 1958. His schoolmates at Yala included Peter Oloo Aringo, later a fellow Cabinet minister.
After school, the Gusii County Council employed Onyonka until 1960 when he benefited from the famous education airlifts with a scholarship to the University of Puerto Rico at San Juan in the US. He graduated in 1965 and, in 1966, joined Syracuse University, New York, where he enrolled for a masters’ degree in economics, specialising in money and banking. Upon completion, he embarked on doctoral studies at Syracuse. It was then that Onyonka joined the University of Nairobi as a tutorial fellow, as he carried out research for his PhD degree. He pulled it off in 1969.
Onyonka closely worked with Prof Terry Ryan of the Statistics Department, who helped him with statistical work for his doctorate degree. Thereafter, the University of Nairobi employed him as a lecturer in the Department of Economics.
But he had political ambitions. It dawned on him that the Kisii considered an unmarried man unsuitable for leadership. To qualify as a serious parliamentary candidate, and to start a family, he married an undergraduate student Beatrice Mughamba from Moshi, Tanzania. At the time, Beatrice was a student of home economics at the University of Nairobi. Her peers included Chris Obure (now a Cabinet Minister), politician David Kombo and former Permanent Secretary Sospeter Arasa.
Beatrice remembers Onyonka as a dashing young lecturer, whose brilliance and articulate voice dazzled many. She describes him as talented, captivating and humorous. She was, however, attracted to him due more to his dignified and forthright nature and honesty regarding their future marital union. She recalls how his unusual candour played out when Onyonka proposed.
Onyonka and Beatrice married on August 2, 1969. They had six children: Elisabeth Kwamboka (1970), Tolia Nakadori (1972), Kiki Christopher Robert (1975), David Wilfred (1976), Timmy Eric (1977) and Naanjela Anna (1980). Beatrice describes Zachary as a loving husband and father. Even when he was engaged in public functions, Onyonka called home to say he wanted the family to share a meal in the evening.
When Onyonka worked at the Gusii County Council before he left for further studies in the US, he was married to Teresia Nyakarita, with whom they had a son, Momoima Onyonka, now an Assistant Minister for Foreign Affairs. When Onyonka left, Teresia remarried and moved on with her life. Momoima finally linked up with his father when he was a Form Three student at Kisii High School. Beatrice accepted Momoima as her son. Before Onyonka died, Momoima teamed up with and helped his father in his political campaigns. It was then that Momoima polished his political skills.