 Koriwhai of the Ngāpuhi had been murdered by some members of the Ngāti Whātua and Ngāti Maru tribes.This murder bought back memories of the defeat that the Ngāpuhi had suffered at the battle of Moremonui.So Hongi Hika decided to help Te Whareumu, to whom Koriwhai was related, and at the same time use the opportunity to wipe out their warlike neighbours of the Kaipara.