In 1831 the richest place in the South Island was a stockade in the swamp, north of the Waimakariri. Kaiapoi Pā held a thousand people and the greenstone trade. By the new year it was ash, and its name had been rewritten as an insult.
The pā went up around 1700, built by the chief Tūrākautahi on a tongue of high ground ringed by swamp on three sides, the nest of the taniwha Kaikaiāwaro, so the old name ran. It became the largest fort in the South Island. Earth banks, tall wooden palisades, a watchtower over the gate called Kaitangata, and gates named Hiakarere and Huirapa where the land approached. Inside, the wharenui faced north and the town's ovens sat south of the walls, and everyone within reach of the trading routes came: pounamu from the Arahura River, muttonbirds from the islands off Stewart Island, obsidian from Mayor Island, kūmara grown on the flats. The greenstone trade made it wealthy beyond any other southern stronghold. A thousand people lived behind those walls.
And it had made an enemy.
In the late 1820s Te Rauparaha of Ngāti Toa came to the gate as a trader, muskets for greenstone. But a Ngāpuhi warrior staying at the pā overheard the visitors planning an attack for the next morning. The Ngāi Tahu struck first and killed the leading Ngāti Toa chiefs, among them Te Pēhi Kupe. Te Rauparaha alone slipped away, and he went north carrying the debt.
He came back four years later, this time to burn the debt off. The siege ran three months, and even then the walls held. The Ngāi Tahu had no muskets, so they sat behind the palisades and waited for the attackers to tire. The end came from the weather. During a skirmish a shelter caught fire, and the nor'wester drove the flames into the wooden palisades. The walls caught. Ngāti Toa poured through, captured the leaders, and killed the people. That night the old accounts say the victors renamed the place: Kaiapohia, the pilings of bodies to eat.
The pā was never rebuilt. Its survivors gathered with their kin at Ōtākou and met Te Rauparaha on the road south, and he turned back for the North Island without pressing further. But the loss stayed in the land. The field at the corner of Preeces Road and Kaiapoi Pa Road is wāhi taonga now, and the earthworks still hump up under the grass. The monument raised there in 1899 stands on the southern side, where the wall used to be, facing the empty nest. The greenstone trade that made the pā rich went north with the man who burned it. The town of Kaiapoi, which took the fort's name, grew up in the 1850s across the river, out of sight of the ash.