I Am Looking for History Regarding My 3x Grandfather

I am looking for any information Regarding my Great Great Grandfather, any information welcome, as well as my Great grandfather Te Koeti Rangimauriora and my Grandfather Rawiri Tamatea A.K.A. Koeti Tamatea.

My mothers name was Arohia Mavis Mitchell-Tamatea

Birth dates, were they are buried plus any thing that can help with doing my family tree.
Thank-you.
Rakataha Ralph Elsmore