James West Stack, born on 27 March 1835 in a tent in a Maori pa at Puriri in the Thames district, New Zealand, was the oldest of seven children of the missionary James Stack and his wife, Mary West. He married Eliza Rachel Jane Jones on 28 January 1861 at Auckland; they had seven children. He spent his childhood with his parents at Church Missionary Society stations in the north of the North Island and at East Cape. Living remote from European contact at Rangitukia, near Ruatoria, from 1842 to 1845, James learned to snare birds and catch eels and grew up familiar with the Maori world, although conscious that he himself belonged to the missionary one. His views on the conduct of the pre-Christian Maori were influenced by his father's unfortunate experiences at mission outposts in New Zealand. In 1846 James was sent to school at St John's College, Auckland, but left for Sydney the following year with his father, whose health and sanity had collapsed. James spent a year at Sydney College (later Sydney Grammar School), before the family travelled back to England, arriving in May 1848.
In London he was supported by the CMS at a commercial college until the age of 14, but it was his own developing love of books which shaped his mind. Although employed by the CMS as a clerk, he had no intention of becoming a missionary himself. The unexpected death of his much loved mother in 1850 and a reunion with the Reverend William Williams in 1851 caused a change of heart. Although too young to be a missionary, he was accepted as a teacher and spent a year at the CMS Training College at Islington. The presence of Tamihana Te Rauparaha in London gave him a chance to revive his fluency in Maori as interpreter and companion. Stack sailed for New Zealand on 22 July 1852, on the Slains Castle, with Tamihana among his fellow passengers, and arrived in Dunedin on 9 November 1852; he disembarked at Wellington on 7 December.
From 1853 to 1859 James Stack taught the boys at the industrial school at the CMS station situated first at Maraetai, at Waikato Heads, and then at Te Kohanga, under the Reverend Dr Robert Maunsell, who supervised his continuing studies. He then accepted Bishop Henry Harper's invitation to take up the work of the newly founded Maori mission of the diocese of Christchurch, reluctantly leaving the CMS. He arrived in Christchurch on 16 August 1859, was ordained deacon in 1860 and became a priest in 1862. The mission house, church and school were sited at Tuahiwi, away from European settlement, on 20 acres of land gifted by the Maori from the Kaiapoi Reserve. Although initial evangelism had already been carried out by Maori converts from the North Island, and the Wesleyans (with whom Stack worked cordially) were already in the field, there was considerable enthusiasm for the new resident European clergyman. Stack travelled very extensively around Banks Peninsula and occasionally as far south as Stewart Island.
Stack's long-term hope was to set up a Maori church within the Church of England, and the ordination of the Reverend George Mutu as deacon in 1872 appeared to offer some prospect of its fulfilment. But the church suffered during the 1870s, not only from lack of money but more seriously from the teaching of the prophet Hipa Te Maiharoa, who drew many throughout the district. Although those around Kaiapoi stayed Anglican, Stack believed that the bitter sense of betrayal over the loss of land had 'blighted all our work'. He wanted the government to prevent the leasing of Maori land on disadvantageous terms, and to encourage Maori landholding to develop along European economic and social lines. He considered the reserves were 'ridiculously small', showed impatience at the government's slowness in settling claims and was aware of extreme poverty among the South Island Maori, who were feeling the full weight of European settlement by the 1870s. He tried to influence the government to act for those suffering hardship.
When the mission house at Tuahiwi accidentally burned down on 5 May 1870 there were no funds to rebuild it, and after a period in temporary accommodation at Kaiapoi, the Stack family moved to Christchurch in 1874. His proficiency in the Maori language had made it possible for Stack to supplement his meagre clerical income by taking an appointment in 1860 as government interpreter. He later became inspector of native schools in the South Island, as well as presenting annual reports to the Native Department on the condition of the Canterbury Maori. In 1880, with retrenchment, Stack lost his government employment but accepted the charge of the European parish of Duvauchelle; this gave him access to the Banks Peninsula Maori, with whom he rebuilt some church connections. In 1883 James and Eliza Stack visited England, returning to a series of parishes: St Albans, 1884–85; Kaiapoi and Woodend, 1885–88; and, on retiring from the Maori mission (possibly in recognition of Eliza's advancing years), Fendalton, 1888–98. He became honorary canon of Christchurch Cathedral in 1894. In 1898 Canon and Mrs Stack left New Zealand, living with her brother in Bordighera, Italy, until 1907, and then in Worthing, England, where Stack died on 13 October 1919.
As a member of the Philosophical Institute of Canterbury, Stack published a number of papers on Maori subjects. His South Island Maoris: a sketch of their history and legendary lore (1898) was based on a paper delivered to the institute in 1877, and included a list of his informants. He also contributed the section on Maori history to H. C. Jacobson's Tales of Banks Peninsula (1884). Kaiapohia: the story of a siege (1893) gives a version of the background to the sacking of the pa and incidents during the siege; it also conveys something of its economic importance. Stack organised the erection of a column at the site, with a brief text in Maori and English commemorating its history. Koro (1909) indirectly provides a background to much of Stack's mission work.
Stack was consulted as an expert on Maori matters by his friend Julius von Haast at the Canterbury Museum. He wrote on Maori subjects for the local press and gave public lectures, hoping to enlighten European society in Canterbury, which largely ignored the Maori world. He chose, on the whole, to omit genealogies from his accounts, on the grounds that these would confuse the European reader for whom his work was intended. On the other hand, he kept close to Maori phrasing for his myths and histories, in order to preserve authenticity. Artefacts collected by Stack, now in the Canterbury Museum, are of very great value. He made a significant contribution to the preservation of Maori placenames, arguing from his knowledge of local tradition that 'Every part of the country was owned and named', and the detailed maps of areas round Banks Peninsula which he sent to the provincial surveyor in 1896 bear out that claim.