Te Whareumu (died 1828) was the ariki and warrior chief of Ngāti Manu, a hapū within the Ngāpuhi iwi based in the Bay of Islands in New Zealand.
He was a warrior chief of the highest mana in pre-European times and well respected by the early missionaries and traders, to whom he provided the greatest protection.
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.
Te Hihi managed to stop Hongi Hika from destroying his relatives by presenting the warrior with a fine old mere (greenstone weapon).
Te Whareumu was killed in 1828, in the Waima district of the Hokianga, seeking utu (revenge) for the death of his relative Tiki, a son of Whetoi (aka Pomare I).
This shows the complex nature of utu, when Tiki felt offended by the theft of some pigs by members of the Te Mahurehure tribe, he went to their land seeking redress, in this case, sweet potatoes and was shot while removing them.
Te Whareumu's death threw the whole area into a state of nervous tension as the other Bay leaders debated what revenge was required and the hapless missionaries tried valiantly to restore some kind of peace.