Wahanui was raised in the Waipā Valley as a Christian, and attended the Wesleyan Native Institution at Three Kings College in Auckland, afterwards returning to Te Kopua to live with his people.

[1] In the late 1850s Wahanui organised a mail service between Te Awamutu and Napier, and set up a tribal administration and law enforcement system which attracted the positive attention of John Gorst.

After the war ended he became an important leader of Ngāti Maniapoto and a principal adviser to the Māori King, Tāwhiao.

Wahanui, Rewi and Taonui signed a petition which was presented to Parliament in June 1883; they criticised the government for legislation which ran contrary to the Treaty of Waitangi.

He was also given a gold medallion which would allow his family free travel via the railway for a few generations, but every promise made by Stout was ignored by the Government.