According to the British, this represented a challenge to the sovereignty of the Queen, which resulted in the year-long battle for Taranaki in 1860, Mr Simons said.
Maori warriors from Waikato assisted in the battle and Governor Gore-Brown moved to contain it.
The Government knew Tauranga was strategically important and was being used by traders to run guns and other supplies to Maori in the Waikato so in January 1864, about 600 British troops under Lieutenant Colonel Greer (after whom Greerton is named), arrived in Tauranga to blockade the harbour.
On hearing that a British force had arrived, a contingent of Ngai Te Rangi warriors established a pa at the edge of the mission land on a ridge at Pukehinahina, the site now occupied by St George's Anglican Church.
The British believed the Maori were going to attack so called in reinforcements, which resulted in the gathering of about 2000 men.
In the evening of April 28, 1864, half of the British soldiers (68th regiment) walked around the pa and took position at the rear while the 43rd regiment waited at the front, ready to attack the following morning.
At daybreak, the soldiers launched a ferocious attack on the Maori which lasted all day. As dusk approached, Lieutenant General Cameron (after whom Cameron Rd is named) thought they had sufficiently breached the pa and stormed it under heavy fire.
"Ferocious hand to hand fighting took place," Mr Simons said.
About this time the 68th regiment surged in from the back of the pa, which forced the Maori into the pa like sardines. It is thought the 43rd regiment thought Maori reinforcements had arrived, so they suddenly repulsed and ran back to their lines.
The battle was a Maori victory. The British lost 31 men and had 80 wounded while about 25-30 Maori were killed and an unknown number injured.
Despite the bloodshed, female warrior Heni Te Kiri Karamu gave water to Lieutenant Colonel Booth, who lay dying in the trenches. Later that evening, the Maori evacuated the pa and the British occupied it the following day. Lieutenant Colonel Booth lived long enough to tell the tale of compassion before he died.
After the battle the British reinforcements left Tauranga and the remaining troops were told to attack any Maori immediately if they saw any attempt to build another pa.
Two months after the Battle of Gate Pa, on June 21, 1864, a British patrol found a large Maori force beginning to build a fortification at Te Ranga.
"The next morning there was a very brief battle and 158 Maori were killed. They didn't even have time to entrench properly. Fourteen British soldiers were killed," Mr Simons said.
After the Battle of Te Ranga, Maori warriors planned to attack the mission station, however they formally surrendered instead.The aftermath of the battles saw large confiscations of Maori land and the establishment of the fledgling town of Tauranga.
The remains of the Maori warriors who died in the Battle of Gate Pa lie somewhere near the church in an unmarked grave, while the bodies of the fallen British soldiers (about 30) were buried at the Mission Cemetery in downtown Tauranga.
Mr Simons said the Battle of Gate Pa and Te Ranga was a time of extreme violence but also compassion and human kindness, as demonstrated by the female warrior.
The 150th commemorations of the battles occur on 29 April and 21 June 2014. A large and diverse range of events citywide are being planned to mark the occasion.
Next month, Mr Simons will give a talk about the Treaty of Waitangi at the St George's Anglican Church. This will take place on Sunday, February 3 from 2-4pm.
