"If you come any further south I'll rip your stomach out with a barracuda tooth."
Te Rauparaha was chief of the lower North Island iwi, Ngati Toa. He had a strong power base on Kapiti Island, it was here he started a successful trading base with European ships, and trading mainly flax fibre which is very good to make ropes for sailing. Te Rauparaha was short but made up for this with his fearsome, cunning nature and he as always getting opportunities to increase his mana (power).
"kill and enslave them."
Te Maiharanui of Ngai Tahu was a very powerful, fearsome and well known chief, he was so feared by people that everyone avoided stepping in his shadow, as they thought it might break tapu. Te Maiharanui lived in a big and successful village, which was perfect for European trading ships to anchor and trade. Te Maiharanui's undertaking was beginning to threaten Te Rauparaha's very successful trading business.
Te Rauparaha had his sights set on Ngai Tahu, where flax trade was threatering his own business and trading ships were beginning to bypass through to Takapuneke. The perfect opportunity arose when Kaikoura chief Rerewaka told everyone he would rip Te Rauparaha's belly out with a barracuda tooth if he were to raid any further south. This insulted Te Rauparaha and his mana and they were quick to defend it.
So on October 1829 he launched a war party and quickly defended their mana by killing and enslaving over 1400 villages, and Rerewaka meet a torturous and painful death. Te Rauparaha pursued and robbed Omihi where those who escaped had hid. He then wanted to take down Ngai Tahu's trading headquarters at Kaiapoi but was a lot harder to gain access too.
Te Rauparaha gathered seven of his high ranked generals. They arrived under the impression that they were trading greenstone and were granted access to start negotiations. But there was a surviver from Omihi who arrived and told the Ngai Tahu chiefs of Te Rauparaha's previous murderous acts. Te Maiharanui and his chiefs attacked to catch the Ngati Toa chiefs off guard.