The son of Greek migrant parents, Jackomos was born in Collingwood and grew up in the Great Depression, mixing with people from a range of backgrounds. He was at different times a welfare worker and activist, a public servant in Aboriginal affairs, an historian archivist and genealogist. Loved by many, Jackomos's life was not without controversy as he was a non-Aboriginal man, with an Aboriginal family, living and moving in an Aboriginal world and working for Aboriginal causes. He maintained strong connections with his Greek heritage and the RSL, of which he was a loyal member, and visited Brunei so often that it became his second spiritual home.