Te Purewa was born at Whaitiripapa, in the valley of Rūātoki. His date of birth is unknown. When he was young he was also known as Te Oripa, but this name is rarely used. Te Purewa had links with many hapū of Tūhoe: Ngā Potiki, Ngāti Huri (Tamakaimoana), Ngāi Tamatea, Ngāti Rongo and Te Māhurehure. Through his mother, Kōkāmutu, he had connections with Ngāti Whakaue of Te Arawa, and through his father, Tihi, with Ngāti Kahungunu. Te Purewa had five wives: the first was Hinekura, of Ngāti Rongo. They had three children: Te Āhuru, Te Whakatangihau and Horohoro. Te Āhuru later inherited his father's mana and authority. Hinekura was taken prisoner by Te Whakatōhea of Ōpōtiki after a raid on the settlement of Ōtairoa in Rūātoki. She was later released. Te Purewa's second wife was Rangitahu. Their child had the same name as his first wife, Hinekura. Te Purewa also married Taia and Rangitīkawea. After the death of his elder brother, Tamahore, he married one of Tamahore's widows, Hinekiri.
Te Purewa was the third of four sons. Te Oata, the eldest, is only remembered because of his seniority. Tamahore, Te Purewa and Tūmatawhero were held in higher regard. They were referred to as Te Tokotoru-ā-Kōkāmutu (the triad of Kōkāmutu). In retelling the adventures of Te Purewa, Tamahore and Tūmatawhero should not be omitted as all three travelled and waged war together. It was not until after Tamahore's death that Te Purewa ventured out alone and became well known on his own account.
Te Tokotoru-ā-Kōkāmutu came into prominence during the early 1800s when Tūhoe began to mobilise its forces either to repel intruders or to assist neighbours in settling feuds. Te Tokotoru-ā-Kōkāmutu were present at the battles which devastated Te Whāiti during the expulsion of Ngāti Whare and Ngāti Manawa hapū. The vacant lands of Te Whāiti were later settled by Ngāti Pūkeko of Whakatāne. The presence of Ngāti Pūkeko kept Ngāti Whare and Ngāti Manawa in check; Tūhoe and Ngāti Pūkeko conducted joint campaigns against them. During one of these campaigns, at Okarea pā about 1818, Te Purewa's son, Te Āhuru, was wounded.
The peace between the two tribes was ended by Te Kihi of Ngāti Pūkeko when he attacked Ngāti Tawhaki at Papueru in Ruatāhuna. Te Tokotoru-ā-Kōkāmutu were among the Tūhoe forces which expelled Ngāti Pūkeko; Tūhoe became the sole occupants of Te Whāiti. As a result, Tūhoe became embroiled with Tuhourangi and Ngāti Rangitihi sections of Te Arawa. Between about 1814 and 1821 a series of confrontations took place. Te Tokotoru-ā-Kōkāmutu played a prominent role in the last of these, at Pukekaikāhu near Lake Rerewhakaaitu.
Before this battle, a challenge to a duel was issued by Tionga of Te Arawa. Tamahore was ready to accept it for Tūhoe but Te Purewa stopped him from doing so, reminding him that he carried the responsibilities of chieftainship and it was wiser that he, Te Purewa, should maintain the role of 'the strong shoulder'. Tamahore agreed. The duel was fought with taiaha. Eventually the fighters simultaneously lunged with the blades of their taiaha towards each other's head. Te Purewa struck home first, instantly killing Tionga, but the momentum of Tionga's taiaha still had enough force to daze Te Purewa so that he sank on to one knee. Te Wahakaikapua, Tionga's second, darted forward to attack Te Purewa. Te Wahakaikapua came too close and Te Purewa thrust up with his mere and killed his second opponent. He said: 'Lie there, the double victims of the one born of Kōkāmutu.' The expression is still uttered in formal farewells to two persons whose deaths are fairly close. After the battle at Pukekaikāhu, Te Arawa came to Ruatāhuna to seek the return of the bones of their dead. Peace was there established by Te Purewa on behalf of Tūhoe and by Mokonuiārangi for Te Arawa.
Soon after this event, Te Purewa featured again in an epic duel, this time with Peehi Tūkorehu of Ngāti Maniapoto, who was leading a force through Te Whāiti. The two leaders agreed to a duel; free passage would be granted to Tūkorehu if he triumphed. The duel ended when neither could defeat the other. Peace was made with an embrace and exchange of mere, and a declaration of undying friendship. This peacemaking had far-reaching effects; it was a major reason for Tūhoe's assisting the people of Tūkorehu and Rewi Maniapoto at Ōrākau in 1864.
Te Tokotoru-ā-Kōkāmutu also waged war against Ngāti Tūwharetoa of Taupō. A chief of that tribe, Taihākoa, was killed at Te Arikirau in Ruatāhuna; this episode is known as 'Te Kanohi kitea o Taihākoa' (the seen face of Taihākoa). The name indicates that Tūhoe believed that Ngāti Tūwharetoa had assisted Ngāti Whare to wage war against them. Under the chiefs Te Umuariki, Taiturakina, Tūīringa, Te Purewa and Tamahore, and their war god, Te Rehu-o-Tainui, who had been invoked at Pukekaikāhu by the priest Te Ūhia, Tūhoe marched to Taupō. The battle that followed was the last between Tūhoe and Ngāti Tūwharetoa; Te Purewa concluded peace with Herea Te Heuheu Tūkino I. As well, it was the final battle in which Te Tokotoru-ā-Kōkāmutu fought as a unit.
After Taupō, Tamahore joined a Tūhoe party on a peaceful visit to Te Kihi of Ngāti Pūkeko at Whakatāne. The party was involved in a fight with a Te Whakatōhea war party and Tamahore was killed. He had been a leader in many of Tūhoe's undertakings, and was regarded as an outstanding orator.
Tamahore had married Hinetemoa of Ngāti Rongo, who was a composer. When she was nursing her new-born son, Tamahore began an affair with her sister, Hinekiri. Hinetemoa ran off into the bush with her son, Te Pahī. After Tamahore had failed to find her, he went to live at Ōhāua-te-rangi, north of Ruatāhuna. There he confessed his sins to his people. During his confession, he slipped and lacerated himself until he bled. To shame himself further, he rolled in a bed of embers and ash; at Ōhāua-te-rangi there is a red rock called 'Ngā toto o Tamahore' (Tamahore's blood). Some years later, while Tamahore was hunting for pigeon, his party heard the voice of a lone woman singing. On listening to the words, Tamahore knew that it was Hinetemoa. She came out from hiding with Te Pahī, now grown-up, standing by her side. To celebrate this reunion with his wife and son, Tamahore sang a song for the occasion:
Ka mea Tāwera ē
Me kawe rawa ia ki te wai
Kia wetewetekiatō kiri ē
Ki te wetewete nā Kahukura i te ati ē.
(Tamahore, using the name Tawera, asks that his son be taken to the water to be cleansed and dedicated to the life of a warrior under the deity, Kahukura, to ensure success in all he does. This waiata remains one of those most often sung by Tūhoe.)
But Te Purewa, not Te Pahī, set out to avenge the death of Tamahore. After raising a force to take revenge on his brother's killers, Te Purewa departed on his own. He immediately attacked Ngāti Pūkeko, who lived north of Tāneatua, at Te Hūrepo where his brother had been killed. Only after he had killed a number of them did he discover his mistake; Ngāti Pūkeko told him that Te Whakatōhea were responsible. Te Purewa headed for Waiōeka, where he came across Te Whakatōhea at Whitiwhiti, in the Ōhiwa district. He felled 15 of them before his force arrived. The rest were overtaken at Te Papa on the Waiōeka River. On his return, Te Purewa decided to establish a permanent hold over the lands of Waiōtahe Valley by attacking Ūpokorehe and Te Whakatōhea at Te Kahikatea.
From that time, Te Purewa often ventured alone, even when the odds against him were great. After Te Kahikatea, he fought at Waikaremoana against Ngāti Ruapani and Ngāti Kahungunu, for some five years from 1823 to 1827. Tūhoe victories were followed by peacemaking. At the peacemaking with Hīpara of Ngāti Kahungunu about 1827 at Waikaremoana, Tūhoe were represented by Te Purewa's son, Te Āhuru; the two mountains, Kahutārewa of Ngāti Kahungunu and Turi-ō-Kahu of Tūhoe, were symbolically joined in marriage, an enduring reminder to the tribes to respect and maintain the terms of peace.
But Te Purewa's battles were not yet over. To the north, Ōpouriao and Rūātoki had to be cleared of Ngāti Awa and Ngāti Pūkeko settlers occupying the lands where they had taken refuge from Ngāpuhi, under Pōmare I. The battles between these tribes and Tūhoe spanned some 17 years, until in the mid 1830s, Ngāti Awa and Tūhoe held a series of peacemaking meetings. Two such meetings had already been completed when Te Purewa visited Ngāti Awa at Te Kupenga, at Te Teko, to make peace. Some sources suggest that Te Purewa sent his son as he was getting too old. But old age did not stop him from conducting his own brand of diplomacy. While he sent Te Āhuru, Parāone and Pētera Koikoi to Pūpūāruhe in Whakatāne to conclude peace negotiations with Ngāti Awa and Ngāti Pūkeko, Te Purewa himself arranged peace with Taupiri and Tamaiārohi of Ngāti Pūkeko at Te Awahou, near Tāneatua; he gave them the right to use the lands between Te Hūrepo and Te Awahou.
Te Purewa assumed the task of upholding Tūhoe's mana over lands from Waimana north to Waiōtahe Valley, and from Te Hūrepo south to Rūātoki, including Ōpouriao and the Ōwhakatoro Valley. His brother, Tūmatawhero, stayed at Maungataniwha and Ruatāhuna, to guard against invasion there. Not satisfied with these holdings, Te Purewa included the lands of Waiōhau under his mana as well. At Te Karangi, in Waiōhau, he removed the rights of Te Rangitūkehu (a Ngāti Awa chief with whom he had concluded peace at Te Kupenga) by killing the pigs the latter was keeping there. He occupied the lands, waiting for Te Rangitūkehu's challenge. None came. Te Purewa established a settlement and cultivation, which he left his nephews Taurua and Roihi to guard.
Te Purewa was constantly on the move, travelling and overseeing settlements and lands under his mana. It was he who introduced the cultivation of potatoes to Rūātoki. His son, Te Āhuru, planted the first peach tree in Rūātoki, at Waikirikiri, having obtained it from the CMS missionary S. M. Spencer. Within the blocks of lands he held, Te Purewa set up signs of his occupation. Overlooking Waimana and Ōpouriao he built a pā at Te Tawhero, where he constructed two houses, Pūkahu for himself, and Tahitikahu for Te Āhuru. When Te Āhuru died he was buried at Te Tawhero. A dog, which had been seen burrowing into the grave, was chased and shot while swimming across the river of Hinemataroa (Whakatāne). That river became tapu and remained so for many years, until the tapu was removed by Tamahore's great-grandson Kererū Te Pukenui.
In August 1836 Te Purewa went to Te Arawa to assist his mother's people, Ngāti Whakaue, against Ngāti Hauā. When he arrived, he was asked where the rest of Tūhoe were. He said that he had come alone. Te Arawa replied that a single flick of Ngāti Hauā's finger would sweep him aside; success against Ngāti Hauā seemed impossible. But under Te Purewa's guidance, Te Arawa lured Ngāti Hauā from their pā with jeers and insults. When they came out Te Arawa withdrew, and enticed Ngāti Hauā to pursue them. Te Purewa hid and attacked the pursuers from behind. When he was seen striking down the pursuers, Te Arawa turned and overcame them. This battle was known as Te Matai Puku and appeared to be Te Purewa's last battle before his death six years later at Tauanui, near Ngāmāhanga, south of Rūātoki, possibly in 1842.
In the last 30 years of his life Te Purewa had firmly established himself as a great leader. Throughout the lands of Tūhoe there are many physical reminders of him. One of the pillars in the meeting house, Te Rangimoaho, at Te Rewarewa marae, Rūātoki, represents Te Purewa. A proverb of Te Māhurehure hapū of Te Rewarewa marae acknowledges Te Purewa as its founding ancestor. On the mountain range of Taiarahia, overlooking the marae, are Te Purewa's pā Te Tawhero and Taumata-o-Te Puia. At the town of Tāneatua there is the stream Awahou where Te Purewa concluded a peace settlement with Ngāti Pūkeko. In the valley of Ōwhakatoro there is a hill called Te Taumata-o-Te Purewa; below this hill is a grove of trees named after his wife, Hinekura. The stream Ruangārara close by was named after Te Purewa's tūtū (a tree used for spearing birds), for at the root of the tree was a hollow occupied by a lizard (ngarara). At Waiōhau there is 'Te pūtaewa a Te Purewa' (Te Purewa's potato heap), indicating that the people there lived under his authority and protection and anyone attacking them would answer with their lives. His village, Aropaki, is at Ōhāua-te-rangi. The site of the pā, Whakaari, which he built during the wars against Ngāti Kahungunu, is at Waikaremoana. Another landmark at Waikaremoana is called 'Ngā hina o Te Purewa' (Te Purewa's white hair), so named to acknowledge him in his later years.
Te Purewa achieved a reputation for fighting and warfare, and for ending all human slaughter and cannibalism among his own people. It was Te Purewa who established peace at Taupō with Ngāti Tūwharetoa; at Ruatāhuna with Te Arawa; at Waikaremoana with Ngāti Kahungunu; at Te Teko with Ngāti Awa; and at Te Awahou with Ngāti Pūkeko. He held mana over the lands and people of Waimana, Rūātoki, Ōpouriao, Ōwhakatoro and Waiōhau. In his time he was the most powerful warrior among Tūhoe. Some saw him as 'atua whakahaehae' (a terrifying demon). He had a forceful character and it was most unwise to offend him. He richly deserved the title 'Pakihiwi kaha o te huatahi a Kōkāmutu' (the strong shoulders of the lone son of Kōkāmutu).