Samson Mwita Marwa was born in 1932 in the Bukuria District, then part of the British Kenya Colony.
He was educated at the intermediate school in Itibo, and later attended the teachers' college in Kisii.
[2] In 1963, Marwa was elected to the Nyanza Regional Assembly, representing the Kuria District as a member of the Kenya African National Union.
[5] During his tenure in parliament, Marwa campaigned for the opening of an agricultural training center in Kuria, but was rebuffed by Maina Wanjigi, the assistant minister of agriculture, who considered Kuria to be too remote.
[7] Marwa was a polygamist, and had at least eight children, including prominent journalist Chaacha Mwita.