The Wanganui settlement had been established by the New Zealand Company in 1840 on land supposedly bought by William Wakefield in November 1839. By 1845 the settlement had grown to about 200 people and about 60 houses. The settlement was surrounded by about 4000 Māori and although settlers engaged in trade with them for food, there was also friction over their occupation of land which some Māori chiefs denied having sold, with New Zealand Company surveyors reporting obstruction and harassment. Settlers were also nervous about a possible spread of hostilities from the Hutt Valley over disputed land occupation, where one of the most prominent fighters was Te Mamaku, a principal chief of the Ngāti-Hāua-te-Rangi tribe of the Upper Wanganui.
In December 1846, 180 soldiers from the 58th Regiment and four Royal Artillery men were landed at Wanganui with two 12-pounder guns and began fortifying the town, building the Rutland Stockade on a hill at the town's northern end and the York Stockade towards the south. Another 100 soldiers from the Grenadier Company of the arrived the following May. The establishment of the garrison heightened Te Mamaku's expectations of government intervention, and he vowed he would protect settlers but fight the soldiers.