Āpihai Te Kawau was born towards the end of the eighteenth century. His father was Tarahawaiki and his mother was Mokorua, who was descended from the Waiōhua people. Te Kawau's grandfather was Tuperiri, principal leader of Te Taoū hapū of Ngāti Whātua who overran the Auckland isthmus around 1740, defeating the Waiōhua who became the Nga Oho and Te Uringutu hapū of Ngāti Whātua. Thus Te Kawau, the inheritor of several chiefly lines of Ngāti Whātua and known as 'the man of many cousins', had connections which enabled him to become a unifying and leading person in Ngāti Whātua on the Tāmaki isthmus.
In his youth Te Kawau probably fought against Ngāpuhi; Moremonui, a Ngāti Whātua victory in 1807 or 1808, near Maunganui Bluff, was the major battle of the time. Later he was one of the leaders of the war expedition which became known as Te Amiowhenua or 'the encircling of the land'. In 1821 this expedition left Oneonenui, southern Kaipara, for the lower Waikato, where it was joined by Ngāti Maniapoto and others led by Peehi Tūkorehu. It passed through Rotorua to launch an attack against Heretaunga (Hawke's Bay), and reached Te Āpiti (the Manawatū Gorge) before turning east into Wairarapa. There the war party fought Ngāti Hikarāhui, capturing Hakikino pā, near present day Masterton. It is said that the raiders killed and ate all the people they came across in these districts and that Te Kawau slept each night with a basket of human flesh for a pillow. At Te Whanganui-a-Tara (Wellington Harbour) the war party attacked and captured the fortified pā of Ngāti Ira on the island of Tapu-te-ranga, in what is now Island Bay. Tapu-te-ranga was a staging post for voyages across Cook Strait; one report claims that the war party crossed to the South Island.
Moving north again, the expedition attacked Muaūpoko and the Whanganui district, before the remaining section, under Te Kawau, became involved in the wars in Taranaki between their ally Tūkorehu and some Te Āti Awa hapū. Other Te Āti Awa helped the war party to escape to Pukerangiora, the main Te Āti Awa pā. The siege that followed was raised by the Waikato chief Te Wherowhero, after the battle of Mangatiti. The war party added 800 men to Te Wherowhero's army, which returned to Waikato in May 1822 to fight Hongi Hika's Ngāpuhi invasion at Mātakitaki and at Mangauika pā, battles that were disasters for Waikato. In June 1822 Te Kawau returned to Tāmaki and Kaipara, having covered 1,000 miles in one of the longest war expeditions ever undertaken.
Having helped the Waikato forces at Mātakitaki, Te Kawau feared attack by Ngāpuhi, who were also seeking revenge for the Moremonui battle in which two of Hongi Hika's brothers had been killed. Te Kawau now moved his hapū to Pukewhau on the Waipā River; other Ngāti Whātua went north to Mahurangi Harbour. Despite these moves there was fighting over the next two years, warfare against Ngāpuhi culminating in 1825 in the battle of Te Ika-ā-ranganui. Te Kawau left Ōkahu to join his people at this battle, at the conjunction of the Kaiwaka River and the Waimako Stream, inland from Mangawhai, but arrived too late for what was a severe Ngāti Whātua defeat. After Te Ika-ā-ranganui the hapū of Ngāti Whātua on the Tāmaki isthmus scattered, leaving the isthmus depopulated. Only after Hongi's death in 1828 were Ngāti Whātua able to return to Tāmaki, where they resumed their cultivations at Māngere, Onehunga and Horotiu, and their land at Ōrākei.
At Manukau Harbour, on 20 March 1840, Te Kawau signed a copy of the Treaty of Waitangi. Ngāti Whātua were seeking British protection against their Ngāpuhi enemies. Their Māori protector in the 1830s had been Pōtatau Te Wherowhero, and it may have been partly due to their long alliance with him that, although refusing to sign, he did not reject the treaty out of hand.
Shortly after signing the treaty, Te Kawau made available land for a new settlement on the Waitematā Harbour. This decision was reached after a major meeting at Kohimarama, called by Te Kawau as leader of Ngāti Whātua. Discussions were inconclusive until Te Kawau's tohunga, Tītai, went into a trance and uttered the following prophecy:
What is this wind that softly blows
'Tis the warm wind from the north
That blew the nautilus shell ashore
I will go and fetch the carved post
And establish it in the Waitematā
Our desire will then be fulfilled!
This prophecy was taken as an indication that if the centre of government could be established on the Waitematā Harbour the survival of Ngāti Whātua would be ensured. Te Rewiti, Te Kawau's nephew, was sent to the Bay of Islands to invite the new lieutenant governor, William Hobson, and negotiations led to the sale of 3,000 acres of land for the site of Auckland. By the deed, signed on 20 October 1840, Te Kawau and three other leaders received £50 and a quantity of blankets, clothing and goods. As patron of the colony's new capital Te Kawau undoubtedly enhanced his mana. As the settlement of Auckland expanded he was drawn into its affairs, becoming a close friend of William Martin, the colony's first chief justice.
In 1844 he forced the government to make concessions to Māori in penal matters. When one of his tribe, Te Mānia, was rescued from the court where he had been sentenced to imprisonment for petty theft, Te Kawau showed that the government's military force was inadequate to coerce him. A compromise was reached whereby any Māori convicted of theft would pay fourfold compensation for stolen goods as an alternative to imprisonment. The Native Exemption Ordinance was in keeping with Māori values but it also reflected the degree to which Māori leaders were politically dominant. In Auckland Te Kawau maintained the peace on terms acceptable to his tribe.
In the 1840s Te Kawau was also becoming more involved with the Anglican missionaries. His first contact was with Samuel Marsden, New South Wales chaplain, whom he had met on Marsden's 1820 visit; he had offered him spars and accompanied him for several days on a tour of Manukau Harbour and the land to the north, reaching a village of Te Taoū, Ruarangi Hāereere, south of Kaipara. Marsden had been much impressed by Te Kawau's imposing bearing and tall frame, and by his concern for his kin: Te Kawau appealed to Marsden to pray to the Christian god for the recovery of his brother, badly wounded by a spear. Before Te Kawau's conversion to Christianity could be completed, however, Māori custom had to be reconciled with missionary values. He was married to Kirepiro of Te Taoū and had several other wives; his reluctance to give up any of them probably delayed his adoption of Christianity. He was finally baptised by Bishop G. A. Selwyn at the chapel near Ōrākei pā. The ceremony was preceded by a gathering of his people, who decided that he should take the baptismal name of Āpihai, after the biblical Abishai, who was a great warrior.
In 1852 Te Kawau was made assessor for settling disputes between Māori in the Auckland district; the government subsequently awarded him a pension of £50 a year. By then his initial willingness to sell land had given way to caution. From at least the early 1850s he spoke out publicly against land sales, and in 1853 asked Governor George Grey to help ensure Ngāti Whātua ownership of Ōrākei, but further land was lost from the Ōrākei block. The song that Te Kawau composed to farewell Grey may be taken as referring to his fear of losing the Ōrākei land.
The clouds in yonder horizon
Across the sea, are playing with
the winds, whilst I am here
Yearning and weeping for my son –
Ah! he's more than a son to me;
he's my heart's blood.
In 1868 Te Kawau obtained from the Native Land Court a certificate of title to 700 acres at Ōrākei, the last Ngāti Whātua land in the area.
Te Kawau died at Ōngārahu, Kaipara, in mid November 1869. He was survived by his son, Te Hira Te Kawau; and by his daughter, Hera Whakamana, from whom are descended many Ngāti Whātua people. Te Kawau is buried at Kaipara.