The defences at Pukehinahina (Gate Pā) were designed by Pene Taka Tuaia, who is said to have learnt his military engineering during the Northern War of 1845–46. This new pā made extensive use of anti-artillery bunkers (rua) and its concealed trenches were to lull the British into a false sense of security when they stormed it. Numerous bunkers were prepared rather than several large ones so casualties would be minimal should artillery fire breach one.
When the battle came, no more than 15 Māori were killed by shellfire. The pā’s garrison of around 250 was split between two redoubts. About 200 held the main redoubt, which was approximately 80 m long and 18 m wide. Its triple line of trenches had been timbered over and piled with earth for protection. A ditch and bank led to a smaller redoubt consisting of a double line of covered trenches surrounded by a light palisade (pekerangi) which helped to conceal its real strength.
Following his victory at Ōrākau, Cameron arrived in Tauranga with reinforcements on 21 April 1864. A week later he led 1700 men out of camp at Te Papa. Expectations of victory were high. The heaviest artillery bombardment of the war was unleashed on Gate Pā. To prevent any of the defenders escaping, Cameron ordered the 68th Regiment to take up positions behind the pā.
That evening the nine officers whose units were to lead the attack on the pā gathered for dinner at the Elms, the mission home of Archdeacon Alfred Brown and his wife. Only one of them, Assistant Surgeon William Manley of the Royal Artillery, would survive the following day’s assault. Awarded the Victoria Cross for his attempt to save the life of Commander George Hay of HMS Harrier during the battle, he had also returned to the pā to search for more wounded.
At daybreak on 29 April the British force was readied for battle. A skirmishing line facing the Māori position would provide covering fire during the assault. The main assault party of 300 men was made up of soldiers from the 43rd Regiment led by Lieutenant-Colonel H.G. Booth and a Naval Brigade led by Commander Hay. Another 300 men were held in reserve to follow up the initial assault.
Despite their experience of anti-artillery pā, Cameron’s men were sure that they had the firepower to ‘blow the Pah to the devil’ as their 110- and 40-pounder Armstrong guns and 24-pounder howitzers went to work. The pā was bombarded for eight hours, although some eyewitnesses claimed that much of the fire was ineffective. Some shots missed the target altogether, and according to one account the men of the 68th behind the pā were at greater risk of being hit than the Māori defenders. Certainly the range was very short for the big guns, making accurate fire difficult. Nevertheless, progress was made in breaching a corner of the pā. Steady rain turned the soil that was thrown up whenever the earthworks were hit into mud. Around lunchtime a gun was repositioned to fire on the smaller redoubt. At 4 p.m. with no sign of life in the pā, Cameron ordered the assault to proceed.
Booth and Hay decided to attack together. The assault party formed up four abreast in what the military historian Chris Pugsley has described as a ‘clumsy formation’. They would rely on ‘enthusiasm and dash to see them successfully into the pa.’ These qualities were not to be enough.
With his sword raised, Booth waved the men forward. Almost immediately the assault party was met by a ‘very sharp fire’. The breach in the pā’s outer defences was easily negotiated, but Māori firing from concealed trenches soon inflicted heavy casualties. Some British soldiers had the horrific experience of being shot from below. Booth now led many of the 43rd towards the smaller pā. Among its defenders was the only woman still at Gate Pā, Heni Te Kiri Karamu, who had refused to leave her brother’s side when the assault commenced. She took part in the ferocious close-quarters fighting inside the smaller pā which claimed the lives of Booth and many of his men.
When the Naval Brigade entered the main earthworks, some of its defenders apparently fled but were driven back inside by the men of the 68th stationed behind it. A confused battle took place within narrow confines. Then the British reserve force was sent forward. Now hundreds of men were trying to force their way through a narrow gap into the honeycombed interior of the pā. Enough Māori had remained to ensure their control of the trenches. The quick loss of most of the British officers left the assault force with no clear leadership. Those storming the pā from the front fled in panic, believing that the garrison was being reinforced by the Māori re-entering it from the rear. The dead and wounded were left where they fell. The British lost 35 killed and 75 wounded, twice the estimated Māori casualties.
It was now too late in the day for Cameron to contemplate another assault. During the night Rāwiri Puhirake and the defenders gathered their wounded and slipped past the men of the 68th, but not before Heni Te Kiri Karamu performed an act of great mercy. Hearing the cries of the dying Lieutenant-Colonel Booth and several other wounded soldiers, she took them water which she poured into her hands for them to drink from. Later, when the fighting in Tauranga had ended, a British officer, Lt-Col Gamble acknowledged Ngāi Te Rangi as ‘an enemy anything but despicable, either in intelligence or courage.’
Gate Pā was a major disaster for the British military. Some branded the assault party as cowards. The New Zealander described how men ‘ran away howling’. Both the 43rd Regiment and the Naval Brigade were shamed. Defeat at the hands of ‘half-naked, half-armed savages’ was unforgivable – let alone leaving behind the dead and dying. Those present blamed each other for the catastrophe. Cameron was chastised for being too rash by some and overly cautious by others. He struggled to explain the defeat, which significantly dented his reputation.