Hauhau is a Māori term that was applied to a branch of the religious movement Pai Marire, founded by Te Ua Haumēne of the Taranaki tribe in New Zealand in the 1860s. The movement inculcated that Māori would regain land that they had lost to Europeans during the colonisation process of New Zealand.
The movement spread throughout the North Island. Parts of it were usurped by militant Hau Hau which led to war between the colonizing forces and militant Māori forces. It also produced civil war amongst Māori tribes as exemplified by that involving Ngāti Porou between 1865 and the 1870s in the East Cape and Gisborne regions.
Militant Hauhaus promised immunity from bullets, aiming to drive Pākehā from Māori land, and seeking support for the Kīngitanga, the movement to create a Māori nation under a Māori king.
The mindset of the militant Hauhau was revealed by the gruesome killing of the Anglican Reverend Carl Völkner in 1865 at Opotiki which led to reprisals from the colonial militia with confiscation of lands and jailing followed by execution of a local chief and associates, who in more recent times have been accepted as innocent.