The Moriori are a Polynesian people who settled in the then-uninhabited Chatham Islands around the year 1500. Following an intertribal conflict, Nunuku-whenua, a prominent Moriori chief of the Hamata tribe, established "Nunuku's Law", which forbade war, cannibalism and killing in any form.
The law was strictly abided by, and peace was maintained in the Chathams until the islands were invaded by about 900 Māori from two iwi, the Ngāti Mutunga and the Ngāti Tama, in 1835. The invaders had guns and massacred the Moriori, who gathered urgently for a council at Te Awapātiki. Although youths argued in favour of armed resistance, elders ruled that Nunuku's Law could not be violated for any reason. The Moriori population, conquered and enslaved, fell from over 1600 in 1835 to less than 100 thirty years later.