The tribe takes its name from Kahutianui-o-te-rangi, the daughter of Tūmoana. Tūmoana was captain of the Tinana canoe. He returned to Hawaiki where his nephew Te Parata renamed the canoe Māmaru.⠀
The Māmaru returned to Muriwhenua territory, first sighting land at Pūwheke mountain. Te Parata married Kahutianui-o-te-rangi, and their descendants settled the Rangaunu and Tokerau harbours. They spread south to Whangaroa Harbour, Matauri Bay and Te Tī, where they intermarried with the descendants of Puhi, the captain of the Mataatua canoe.⠀
The Tākitimu canoe, captained by Tamatea, landed at Awanui in Rangaunu Harbour. (This connection was once very important; Ngāti Kahu were sometimes known as Ngāi Tamatea.) ⠀
Ngāti Kahu were well known as coastal raiders and traders as far south as the Waipoua Forest, Whāngārei, Mahurangi and beyond. In 1990 a hui-a-Iwi was called to set up a body to be the Iwi authority for Ngati Kahu. This body was to be a runanga and care had to be taken to ensure that it was set up according to traditional Runanga criteria and not government legislative requirements. McCully Matiu played a pivotal role in the setting up of Te Runanga-a-Iwi o Ngati Kahu.