Matangi was of the Ngati Te Whiti and Ngati Tawhirikura hapu and also Ngati Hamua and related to Ngati Mutunga. Matangi was also known as Rawiri Matangi Ruhau or Ruahau. He took the name Rawiri after his baptism. He was the son of Te Ua and Mahanga, and grandson of Aniwaniwa and Tawhirikura and thus a cousin of both Te Puni and Wharepouri and closely related to Ngatata and Pomare. His wife was called Pikia Te Rangi and her sister called Tawhirikura Karopihia was the wife of Hemi Parai of Te Aro Pa. Matangi and Pikia had a daughter Kakea Te Rangi and a son Manihera Te Ngatoru.
He was invited to join the heke in 1824 called Te Niho-Puta which Pomare and others brought to Te Whanganui-a-Tara. Te Matangi then returned to Taranaki and came back to Waikanae in 1832 with Te Puni and Wharepouri in Te Heke Tama-te-uaua. While the others remained at Waikanae, Te Matangi and his son Manihera Te Toru came to Petone at the invitation of Te Mana as he was a relation. They lived first at Matiu Island and then built houses at Ngauranga and shared cultivations with Te Mana at that site. Before Pomare left for the Wharekauri (the Chatham Islands) in 1835 he gave Petone and Ngauranga to Matangi while Mohi Ngaponga was given Paekawakawa and Te Aro. Te Matangi and his son were at Ngauranga before Mohi Ngaponga and Hemi Parai came south from Waikanae. After the major migration of Ngati Tama and Ngati Mutunga to Wharekauri in 1835 Wharepouri returned from the Wairarapa to Okiwi and was invited by Te Matangi to settle at Ngauranga. Later when Te Puni returned from the Wairarapa Matangi invited him to settle at Petone. Te Matangi signed the Treaty of Waitangi at Te Whanganui-a-Tara in April 1840. During the negotiations by Major Richmond over the Deeds of Release, Matangi's son Manihera Te Toru refused the payment offered to them for Ngauranga as it was not large enough.
In 1843 Rawiri Matangi sent a sad letter to his daughter at New Plymouth pleading with her not to sell her land as they had done in Te Whanganui-a-Tara.
Wellington MB no. 1, p.94-96
Wellington MB no. 1C, p.79
Wellington MB no. 9 p.178
Wellington MB no. 11 p.66 - whakapapa
Otaki MB no. 6 p.53-54
Ward, Alan. Maori customary interests in the Port Nicholson District 1820s to 1840s : an overview. Wellington : Waitangi Tribunal, 1998.
Nga Tangata taumata rau : 1769-1869. Wellington : BWB, 1996. p.329
Nga Waahi taonga o Te Whanganui-a-Tara : Maori Sites Inventory. Wellington : Wellington City Council, 1995.
M50 Alexander Turnbull Library M.S. Papers 0083-193 Folder 193