He was the father of the acclaimed Tui Viti, Ratu Seru Epenisa Cakobau, Ratu Tanoa was installed as Vunivalu upon the death of his elder brother Ratu Naulivou Ramatenikutu, who was involved in a fierce power struggle against the Roko Tui Bau, Ratu Raiwalui, which led to his death.
Ratu Tanoa's illustrious son, the celebrated Tui Viti, Ratu Seru Epenisa Cakobau, succeeded him as leader. Following the passing of his elder brother, Ratu Naulivou Ramatenikutu, Ratu Tanoa was appointed Vunivalu in November 1887. His brother's untimely death sparked a bitter struggle against the Roko Tui Bau, Ratu Raiwalui.