[7] Plans for the invasion were drawn up at the close of the First Taranaki War in 1861 but the Colonial Office and New Zealand General Assembly opposed action, and the incoming Governor Sir George Grey (second term 1861–1868) suspended execution in December of that year.

[10] The Waikato–Tainui tribe accepted compensation in the form of cash and some government-controlled lands totalling about $171 million and later that year Queen Elizabeth II personally signed the Waikato Raupatu Claims Settlement Act 1995.

The lack of a clear victory by imperial forces led Governor Thomas Gore Browne to turn his attention to the Waikato, the centre of the Kīngitanga movement, where king Tāwhiao was attracting the allegiance of increasing numbers of Māori across the North Island.

[2] At the same time, however, Grey began planning for war, using troops from the newly formed Commissariat Transport Corps to start construction work on a road from Drury that would run about 18 km south through forest to the Kingite border at the Mangatāwhiri Stream—a tributary of the Waikato River—near Pokeno.

Some of you offered a safe passage through your territories to armed parties contemplating such outrages ... Those who remain peaceably at their own villages in Waikato, or move into such districts as may be pointed out by the Government, will be protected in their persons, property, and land.

Those who wage war against Her Majesty, or remain in arms, threatening the lives of Her peaceable subjects, must take the consequences of their acts, and they must understand that they will forfeit the right to the possession of their lands guaranteed to them by the Treaty of Waitangi.Within a day—before the proclamation had even reached the Waikato[22]—Grey ordered the invasion of the Kingite territory, claiming he was making a punitive expedition against Rewi over the Ōakura ambush and a pre-emptive strike to thwart a "determined and bloodthirsty" plot to attack Auckland.

[25] Cameron wrote: "The bush is now so infested with these natives that I have been obliged to establish strong posts along our line of communication, which absorbs so large a portion of the force that until I receive reinforcements it is impossible for me to advance further up the Waikato.

[29] The turning point for Cameron came in late October when hundreds of Waikato militia replaced regulars at the outposts, another 500 imperial troops arrived from Australia—now giving him a striking force of almost 2000 and a total of 8000 effectives—and a second river steamer, HMS Curacoa, was brought to the front.

The battle cost both sides more than any other engagement of the land wars and also resulted in the capture of 180 Māori combatants, which impacted on their subsequent ability to oppose the far bigger British force.

A second division of 320 men of the 40th Regiment under Lieut-Colonel Arthur Leslie with additional naval backup, were transported by barge further south with the aim of gaining possession of a ridge 500 metres behind the main entrenchment and cutting off any escape.

Without waiting for Leslie's division, which was delayed by adverse conditions on the river, he began his frontal attack, storming the Māori positions across a 600m gap under heavy fire and immediately suffering casualties.

[8] The 183 prisoners were held without trial on an old coal hulk in Waitematā Harbour before being moved to Kawau Island, north of Auckland, but in September 1864 they escaped and eventually made their way back to the Waikato.

By the end of January 1864 the line had become the largest system of Māori fortifications of the land wars, consisting of at least four large pā spaced about 8 km apart, each of which included complex sets of entrenchments and parapets.

He gained the help of two Māori guides, Himi Manuao (James Edwards) and John Gage, who had previously lived in the area, who revealed a route that bypassed it to the west and south to reach Te Awamutu.

A significant engagement took place on 11 February when an assault party from Paterangi ambushed a group of soldiers bathing in a loop of the Mangapiki Stream at Waiari, near the British forward position.

[36][38] Bishop George Selwyn, as garrison chaplain, had been told on 12 February that women, children and elderly would be taking refuge at unfortified and undefended Rangiaowhia, and had been asked to communicate that with Cameron.

With the Armstrong guns firing over their heads, the infantry, cavalry and Forest Rangers moved towards the defensive line before finally charging with bayonets, revolvers and sabres, driving out the Māori.

[35] For Kingitanga supporters, who after the Rangiriri battle had been urged to fight in a "civilised" manner by the British, and had moved their families away from their fortifications to an undefended, open village, the assault on Rangiaowhia was an almost "incomprehensible act of savagery".

[46] Following the fall of the Paterangi line, Wiremu Tamihana, leading one of the two major Kingite divisions, retreated east to Maungatautari to block a British advance up the Waikato River into Ngāti Raukawa territory and Matamata beyond.

[35] Ngati Maniapoto fighters and their allies remained determined to continue the war, but were divided over their strategy: whether to guard the hinterland with large defensive systems on the fringes, or to challenge the nearby occupying forces with a new pā.

[47] Although he strongly opposed the plan, convinced it would result in their defeat, Rewi relented—possibly in return for the loyalty they had shown in crossing the North Island to join the fight for his territory[9]—and accompanied them back to Ōrākau, arriving about 28 March.

For Rewi, a skilled strategist and warrior, the major concerns about Ōrākau were that it had no immediate water supply and, sited on a low hill, overlooked by the nearby "California" ridge, 850m to the southwest, could also be easily encircled.

[48] For two days the villagers, as well as Rewi's forces and the new reinforcements, labored in shifts to strengthen the defences of the pā, located on a slight rise of land in the midst of peach groves.

[9] Early on 30 March two surveyors working at Kihikihi observed through a telescope construction of entrenchments at the Ōrākau pā and immediately passed the information to Brigadier General G. J. Carey, who had been left in charge of the British forces.

Carey, keen to surprise the Kingites, immediately began organising an expedition and at midnight the first of three separate columns, comprising members of the 40th, 65th and 18th Royal Irish Regiments, as well as Forest Rangers and Waikato Militia, set out for Ōrākau with two Armstrong six-pounders, arriving before daybreak.

[citation needed] Realising the strength of Ōrākau, Carey decided to encircle the pā and began shelling it from about 350 metres, though the design and construction methods of the bunkers neutralised the force of the bombardment.

Placing women and children in the middle of the group and their best warriors in front, the Māori broke through the earthworks at the south-east corner of the pā and ran downhill without opposition 200 metres towards a ridge to the south, behind which the some men of the 40th were sheltering.

The group, many of them holding empty shotguns or tomahawks, was pursued by sword-bearing cavalry and hundreds of soldiers who fired on and bayoneted the fleeing Māori; Forest Rangers kept up the chase until dusk.

[52] Sixteen of the British forces died in the three-day battle and 53 were wounded, some of them mortally; while estimates of Māori fatalities range from 80[9] to 160,[50] with half of the casualties coming from the Urewera contingent.

He said the Commissariat Transport Corps (CTC), established in mid-1861, almost two years before the invasion began, was the "vital kernel" because of its efforts in building the southern road and being a separate military supply train.