The principal townships within their area of interest are Taumarunui, Ōwhango and National Park. In the 1820s, some Ngāti Hāua hapū had also settled in Heretaunga (the Hutt Valley). 

In 2017, the Crown recognised the mandate of Ngāti Hāua Iwi Trust to represent Ngāti Hāua in negotiating a comprehensive historical Treaty settlement. 

The Crown signed Terms of Negotiation with Ngāti Hāua on 14 July 2017. On 22 October 2022, the Crown and Ngāti Hāua signed an Agreement in Principle, which formed the basis for this settlement. 

On 21 November 2024, Ngāti Hāua and the Crown initialled a Deed of Settlement called Te Pua o Te Riri Kore. Te Pua o 

Te Riri Kore was then ratified by the people of Ngāti Hāua and signed on 29 March 2025 at Ngāpuwaiwaha Marae, Taumarunui. The settlement will be implemented following the passage of settlement legislation. 

The Office of Treaty Settlements and Takutai Moana: Te Tari Whakatau, with the support of the Department of Conservation, Land Information New Zealand, and other government agencies, represented the Crown in day-to-day negotiations. 

The Minister for Treaty of Waitangi Negotiations, Hon Paul Goldsmith (and his predecessor Hon Andrew Little), represented the Crown in high-level negotiations with Ngāti Hāua. 

In the 1840s, the Crown negotiated with another iwi to purchase land in Heretaunga on behalf of the New Zealand Company and ordered those Ngāti Hāua present to leave under threat of military force. After fighting broke out in 1846, the Crown captured and court martialled Ngāti Hāua tūpuna. One tupuna, Te Rangiātea, was sentenced to confinement for life and died soon thereafter in prison. Another tupuna, Mātene Ruta Te Whareaitu, was sentenced to death and executed by hanging. Another five tūpuna were exiled to Australia. These events served as a catalyst to further fighting between Ngāti Hāua and the Crown in Whanganui in 1847. 

From the late 1850s, Ngāti Hāua joined the Kīngitanga movement and supported their whanaunga in fighting the Crown in Taranaki from 1863. In 1865, the Crown confiscated land in Taranaki which included land in which Ngāti Hāua have interests. That same year the Crown ordered an attack on the Kīngitanga at Ōhoutahi pā. Ngāti Hāua supported the peaceful protest at Parihaka against the Crown’s attempts to enforce its confiscation. In 1881, the Crown invaded Parihaka, arrested Ngāti Hāua people, and destroyed their property. Since the 1860s, Ngāti Hāua have endured intergenerational stigma of being labelled ‘Hauhau’ and ‘rebels’ by the Crown. 

In the 1860s, in order to facilitate colonisation, the Crown promoted laws which provided for the Native Land Court to individualise the customary land tenure of Ngāti Hāua. The iwi boycotted the Native Land Court at times, but had to engage with it to protect their interests. The Crown began purchasing Ngāti Hāua land interests in the 1870s. In 1886, even though many Ngāti Hāua were not aware of the hearings of the Waimarino block, the Court awarded title. The Crown quickly purchased most of the block, including kāinga of Ngāti Hāua, without paying a fair price. 

Meanwhile, Ngāti Hāua defended the southern aukati of Te Rohe Pōtae. In 1885, the Crown secured the agreement of Ngāti Hāua to lift the aukati for the construction of the North Island Main Trunk Railway by making promises that it did not honour, and then purchasing vast areas of land for settlement by way of purchase from individuals. The Crown used public works legislation to compulsorily acquire some Ngāti Hāua land for the Railway, with compensation not always paid. Ultimately, Ngāti Hāua became virtually landless, and were unable to provide for present and future generations. 

In the early 1900s, Ngāti Hāua gave conditional agreement for the establishment of the Taumarunui Native Township on some of their remaining land, though the Crown did not honour those conditions. The Crown promoted legislation which drastically reduced Ngāti Hāua influence over its management, and prioritised settler interests by allowing perpetual leases and purchasing township sections on behalf of the lessees. 

In 1907 the Crown established the Tongariro National Park without consulting Ngāti Hāua. The Crown did not provide Ngāti Hāua with a role in the Park’s management and the environmental impact from the development of infrastructure within the Park has been distressing for the iwi. Furthermore, from 1971 the Crown utilised the waterways in the Ngāti Hāua rohe, including the Whanganui River, for use in the Tongariro Hydro-Electric Power Development Scheme without consulting Ngāti Hāua. 

The Crown also did not consider Ngāti Hāua interests when it compulsorily acquired their land along the banks of the Whanganui River for scenic reserves in the early twentieth century. The Crown compounded this prejudice when it included that land in the Whanganui National Park in 1987. 

The extent of Ngāti Hāua’s land loss has resulted in the erosion of tribal structures and the iwi’s economic base, and an inability to sustain themselves. Consequently, Ngāti Hāua are virtually unable to exercise kaitiakitanga over the forests, waterways, kainga and wāhi tapu of the rohe, and have suffered poverty, poor housing, low educational achievement, and a lack of opportunities for social and economic development. This, in turn, has damaged the spiritual and cultural wellbeing of the iwi, and led to a dispersal of the Ngāti Hāua population to urban centres which has contributed to a loss of community, te reo Māori, and traditional cultural practices. In the face of this, Ngāti Hāua have persistently called for the maintenance and recognition of their rangatiratanga, guaranteed to them by te Tiriti o Waitangi/the Treaty of Waitangi.