At about 1820, the people living there were Ngāti Ira and other groups who traced their descent from the explorer Whatonga, including Rangitāne and Muaūpoko. However, these groups were eventually forced out of ''Te Whanganui-a-Tara'' by a series of migrations other iwi (Māori tribes) from the north. The migrating groups were Ngāti Toa, which came from Kāwhia, Ngāti Rangatahi, from near Taumarunui, and Te Atiawa, Ngāti Tama, Ngāti Mutunga, Taranaki and Ngāti Ruanui from Taranaki. Ngāti Mutunga later moved on to the Chatham Islands. The Waitangi Tribunal has found that at the time of the signing of the Treaty of Waitangi in 1840, Te Atiawa, Taranaki, Ngati Ruanui, Ngati Tama, and Ngati Toa held mana whenua interests in the area, through conquest and occupation.