Wikipedia
Marutūāhu, Marutūahu or Marutuahu is a collective or grouping of Māori iwi (tribe) of the Hauraki region of New Zealand. The confederation is made up of the tribes of Ngāti Maru, Ngāti Paoa, Ngāti Tamaterā, Ngāti Whanaunga and Ngāti Rongoū.
The Marutūāhu tribes are descended from Marutūāhu, a son of Hotunui, who is said to have arrived in New Zealand on the Tainui canoe. The Marutūāhu tribes are therefore part of the Tainui group of tribes. The Marutūāhu confederation is also part of the Hauraki collective of tribes.
Te Ngako (whose descendants are Ngāti Maru) was younger than his half-brothers Tamatepō (whose descendants are Ngāti Rongoū), Tamaterā (whose descendants are Ngāti Tamaterā) and Whanaunga (whose descendants are Ngāti Whanaunga). Marutūāhu married two sisters, Hineurunga and Paremoehau. Hineurunga was the tuakana (eldest sister). This gave Te Ngako the mana of being tuakana to his older brothers. Hence the name given to the descendants of Te Ngako was not Ngāti Te Ngako but Ngāti Maru. The Ngāti Maru of Taranaki are descended from Marutūāhu's brother Maruwharanui. The descendants of a third brother, Marukōpiri, settled on the Whanganui river.