Tensions rose in the mid-1840s as settlers and Māori were left to deal with the consequences of haphazard and often dubious land purchases by the New Zealand Company.

[4]: 65 The Heretaunga (Hutt Valley) area had been lightly and sporadically populated until the 1830s by a number of small tribes (or hapu), which were driven out during successive waves of migration from northern invaders, ultimately leaving the area in the control of Te Rauparaha of Ngāti Toa, who in turn had granted rights of occupation to Ngāti Rangatahi.

[5]: 128–134, 151–152  Taringa Kuri and his Ngati Tama people moved to the Hutt Valley because of incursions on their cultivation land at Kaiwharawhara by settlers and their cattle, while in Porirua Te Rauparaha's nephew and fellow Ngāti Toa chief Te Rangihaeata menaced surveyors and settlers who attempted to take possession of land there.

[5]: 212 [6]: 192 [10]: 90 In January 1841 Secretary of State for War and the Colonies Lord John Russell appointed lawyer William Spain as Land Claims Commissioner to investigate and determine the validity of the New Zealand Company purchases.

[11][10][12]: 113 The New Zealand Company frustrated Spain's efforts to make a full investigation of its entitlement to land[5]: 225  and in June 1843 it pushed ahead with surveying of the disputed Wairau Plains in the South Island, despite requests by Te Rauparaha and Te Rangihaeata to halt pending Spain's decision on the legality of the purchase.

An abortive bid by settlers and company representatives to arrest the two chiefs for impeding them resulted in the bloody Wairau Affray.

[14]: 113 Despite the company's inability to prove it had made a valid purchase of land—and the Treaty of Waitangi's guarantee that Māori would have undisturbed possession of their lands so long as they wished to retain them—Spain in early 1843 ceased public hearings and began serving as an arbitrator or umpire in negotiations between the New Zealand Company and Protector of Aborigines George Clarke Junior on how Māori should be "compensated" for the alienation of their land.

[12]: 114–115, 134–137  Without consulting Māori, the two sides agreed on 29 January 1844 that the New Zealand Company would make a further £1500 payment as compensation "to natives who may be entitled to receive it" for about 67,000 acres, including surveyed sections in the Hutt Valley.

[12]: 125–126, 128–132 Spain convened a special sitting of the Court of Land Claims at Te Aro pā on 23 February where he informed its occupants of the agreement and asked them to sign deeds of release in exchange for payment.

Te Aro Māori demanded further payment, but relented four days later when Ngāti Mutunga chief Pōmare—visiting the area from his new home in the Chatham Islands—advised them to accept the offer.

When he attempted to secure their signatures to a deed of release for their interest in land at Port Nicholson, Te Rauparaha claimed he had previously been unaware it would include payment for Heretaunga, which he now refused to relinquish.

[6]: 193–196 Taringa Kuri then began cutting a line through bush at Rotokakahi, warning government officials it was the northern boundary of "Port Nicholson" land for which the New Zealand Company had secured its deeds of settlement.

But the Hutt Valley Māori reacted with a display of defiance to both Te Rauparaha and the government, expanding their bush clearings and cultivations and protesting that they had never been compensated for their loss of land.

A series of redoubts and stockades were built in the Wellington area, including "Fort Richmond" beside the Hutt River,[note 5] with further small outposts at Boulcott's Farm and Taita.

All were manned by militia until the steady arrival of almost 800 British troops from Auckland and the Bay of Islands, under command of Lieutenant Colonel William Hulme, 96th Regiment, in February 1846.

In mid-February 1846 he visited the Hutt Valley and secured a commitment from Taringa Kuri that Ngāti Tama would quit the area within a week, abandoning the 120 hectares of potatoes they had been growing.

When settlers began moving on to the vacated land and met resistance from some remaining Māori, Grey sent a 340-strong military force into the valley on 24 February.

[6]: 211–212  He then sent a message to Ngāti Rangatahi chief Kaparatehau, demanding that he abandon the village of Maraenuku, beside the Hutt River, and threatened an immediate attack if they had not left by noon the next day, 25 February.

But at daybreak on 16 May 1846 a force of 200 Ngāti Toa and Ngāti-Hāua-te-Rangi warriors, led by Upper Whanganui chief Topine Te Mamaku, launched an attack on the imperial outpost at Boulcott's Farm.

[23] William Allen, ran from his tent and raised his bugle to sound the alarm just as one of the attackers felled him with a tomahawk, almost severing his right arm.

[25] Half the force of soldiers at Boulcott's Farm were quartered in a large barn, around which a stockade of slabs and small logs had been erected and loopholed for musket-fire.

Page, who had snatched up his sword and loaded his gun, rushed out with two men,[27] fought their way from the house in which they were besieged to a barn, where half the force were quartered.

Te Rangihaeata's stronghold was discovered on 6 August at the crest of a steep ridge, surrounded by strong fortifications and three of the British force were killed in an exchange of fire that lasted several hours until nightfall.

Delayed by storms, the kūpapa Māori, including a Ngãti Toa detachment led by Rawiri Puaha, began a pursuit on 17 August through heavy bush across steep ridges, deep valleys and rocky streams, with both sides suffering casualties in sporadic exchanges of gunfire.