In 1807 Waitapu and brother Houwawe from Ngāpuhi were killed at the Battle of Moremonui during an ambush by Ngāti Whātua. As a result of the battle Ngāpuhi lost their leader, Pokaia, and more than one hundred and fifty warriors. So many bodies lay about that seagulls gathered to eat them by the thousands, so much so that the battle became known as 'Te Kai a Te Karoro' (the Seagulls' Feast).
The famous battle Te Ika A Ranganui was intended to avenge the deaths of Houwawe, Hongi’s brother, and his sister Waitapu at Moremonui in 1807. Source: http://mro.massey.ac.nz/xmlui/bitstream/handle/10179/2222/02_whole.pdf?sequence=1&isAllowed=y
It is stated that two half-brothers and a sister and many relations of Hongi Hika were killed at Moremonui. The memory of the brutal death of his sister Waitapu would remain with Hongi Hika forever. Although there are several different versions, one mentioned by Ngapuhi is that Waitapu urged him to flee, while she turned back to distract Ngati Whatua. She had seen the slaughter of her brother Houwawe and half-brother Hau Moka, and was concerned for the continuation of the family line, and the fact that there would be no one left to carry on its honour – remembering no doubt that Hongi had been especially selected by her parents for this role. The words credited to her as she turned back to face the enemy were: “E hoki ana ahau hei whariki mo aku matua” “I am returning to act as a mat for the principal people of my family” Circling back along the cliff tops, Hongi saw Ngati Whatua slice into her body to remove her uterus, filling the cavity with sand. Hence, the name given later to his favourite gun; Teke Tanumia: – a perpetual reminder of the fate of Waitapu. This action was also a symbolical attack on the continuation of the line. Source: https://kaihuvalleyhistory.files.wordpress.com/2015/12/d-journal-four-main-charachters.pdf