The campaign was a sequel to the invasion of Waikato, which aimed to crush the Māori King (Kingitanga) Movement that was viewed by the colonial government as a challenge to the supremacy of the British monarchy.

In late January 1864 British commander General Duncan Cameron—at the time still facing the intimidating Paterangi line of Māori defences in the Waikato campaign—despatched by sea an expedition to occupy Tauranga, through which he believed his enemy were transporting men and supplies from the East Coast.

While Colonel Henry Greer was landed with his force at Te Papa, where they built two redoubts, Captain Robert Jenkins, commander of HMS Miranda, was ordered to blockade the harbour to prevent the arrival of more Māori reinforcements.

Grey withdrew his initial assent for Whitaker's orders to take an aggressive stance and instead directed the Tauranga expedition's commander, Brigadier George Carey, to remain strictly on the defensive, apart from intercepting armed bands en route to the Waikato.

Ngāi Te Rangi chief Rawiri Puhirake taunted Carey in a letter, challenging him to fight, then in April 1864 moved closer to the British base to occupy to a new ridge-top position at Pukehinahina, a locality known to Europeans as "The Gate" because of the presence of a post-and-rail fence and gateway used by Māori to block Pākehā trespassers.

[4][5] Still hoping to provoke an attack, the 250 Ngāi Te Rangi fighters at Pukehinahina enlarged the existing trench and banks and transformed the pā into a system of two redoubts, including a honeycomb of rua, or anti-artillery bunkers.

[citation needed] On the afternoon of 28 April, Cameron launched an hour-long attack on the front of Gate Pā with four batteries of artillery placed at a range of between 350 and 800 metres.

[3] According to accounts by Hēni Te Kiri Karamū and Hōri Ngātai, the first victims of the British cannon shots were Church of England ministers conducting prayers.

[7] Late in the night Greer moved his 700 men from the 68th Regiment across swamps to the east of Gate Pā under cover of darkness and rain to take up a position to the rear of the redoubt to cut off a Māori retreat.

Some in the initial British assault force were shot as they entered the main pā, and inside the redoubt more fell as they engaged in hand-to-hand combat with Māori armed with shotguns and mere (short clubs).

In a sequence of events that is still unclear, fierce fighting erupted, taking a heavy toll on the invaders and panicked British forces began streaming out of the pā.

[8]: 184–88 As night fell, the Gate Pā garrison, assuming the site would be stormed the next morning, evacuated their position, passing through the lines of the 68th Regiment and fleeing across surrounding swamps before dispersing.

[6][11][7] To contemporaries Gate Pā was seen as a shattering and humiliating defeat, with one newspaper noting that the "gallant" force had been "trampled in the dust ... by a horde of half-naked, half-armed savages".

By early June several Ngāi Te Rangi warriors had handed in their guns and naval commodore William Wiseman reported to London that hostilities in the area had ceased.

[8]: 184–88 Despite government hopes of peace, Kingite forces—newly reinforced by hapu of Ngāti Pikiao, from Rotoiti, as well as a Ngati-Porou war party from the East Cape and commanded by Hoera te Mataatai—decided in June to again challenge the British forces.

They selected Te Ranga, a steep but flat-topped ridge about 5 km from Gate Pā, and began working on entrenchments and rifle pits to cut off a bush track.

Chief Tana Taingakawa, Wiremu Tamihana's son from Ngati Haua, wrote to Colonel Moule urging him not to fight Te Kooti in his land.