The Wairau Affray, the first serious clash of arms between Māori and British settlers in the New Zealand Wars, takes place.

The Wairau Affray of 17 June 1843, also called the Wairau Massacre and the Wairau Incident, was the first serious clash of arms between British settlers and Māori in New Zealand after the signing of the Treaty of Waitangi and the only one to take place in the South Island. The incident was sparked when a magistrate and a representative of the New Zealand Company, who held a duplicitous deed to land in the Wairau Valley in Marlborough in the north of the South Island, led a group of European settlers to attempt to arrest Ngāti Toa chiefs Te Rauparaha and Te Rangihaeata. Fighting broke out and 22 British settlers were killed, nine after their surrender. Four Māori were killed, including Te Rongo, who was Te Rangihaeata's wife.

Māori are the indigenous Polynesian people of mainland New Zealand. Māori originated with settlers from East Polynesia, who arrived in New Zealand in several waves of canoe voyages between roughly 1320 and 1350. Over several centuries in isolation, these settlers developed a distinct culture, whose language, mythology, crafts, and performing arts evolved independently from those of other eastern Polynesian cultures. Some early Māori moved to the Chatham Islands, where their descendants became New Zealand's other indigenous Polynesian ethnic group, the Moriori.

The New Zealand Wars took place from 1845 to 1872 between the New Zealand colonial government and allied Māori on one side, and Māori and Māori-allied settlers on the other. Though the wars were initially localised conflicts triggered by tensions over disputed land purchases, they escalated dramatically from 1860 as the government became convinced it was facing united Māori resistance to further land sales and a refusal to acknowledge Crown sovereignty. The colonial government summoned thousands of British troops to mount major campaigns to overpower the Kīngitanga movement and also conquest of farming and residential land for British settlers. Later campaigns were aimed at quashing the Pai Mārire religious and political movement, which was strongly opposed to the conquest of Māori land and eager to strengthen Māori identity. Māori religious movements that promoted pan-Māori identity played a major role in the Wars.