John Eliot (1604-1690) has been called ‘the apostle to the Indians’. This thesis looks at Eliot not from the perspective of modern Protestant ‘mission’ studies (the approach mainly adopted by previous research) but in the historical and theological context of 17th century puritanism. Drawing on recent research on migration to New England, the thesis argues that Eliot, like many other migrants, went to New England primarily in search of a safe haven to practise pure reformed Christianity, not to convert Indians. Eliot’s Indian ministry started from a fundamental concern for the conversion of the unconverted, which he derived from his experience of the puritan movement in England. Consequently, for Eliot, the notion of New England Indian ‘mission’ was essentially conversion-oriented, Wordcentred, and pastorally focussed, and (in common with the broader aims of New England churches) pursued a pure reformed Christianity. Eliot hoped to achieve this through the establishment of Praying Towns organised on a biblical model – where preaching, pastoral care and the practice of piety could lead to conversion – leading to the formation of Indian churches composed of ‘sincere converts’. The thesis starts with a critical historiographical reflection on how missiologists deploy the term ‘mission’, and proposes a perspectival shift for a better understanding of Eliot (Chapter 1). The groundwork for this new perspective is laid by looking at key themes in recent scholarship on puritanism, focusing on motives for the Great Migration, millenarian beliefs, and the desire for Indian conversion (Chapter 2). This chapter concludes that Indian conversion and millenarianism were not the main motives for Eliot’s migration to the New World, nor were his thoughts on the millennium an initial or lasting motive for Indian ministry. Next, the thesis investigates Eliot’s historical and theological context as a minister, through the ideas of puritan contemporaries in Old and New England, and presents a new perspective on Eliot by suggesting that conversion theology and pastoral theology were the most fundamental and lasting motives for his Indian ministry (Chapter 3). After the first three chapters, which relocate Eliot in his historical context, the last three chapters consider Eliot’s pastoral activities with the Indians. These have usually been understood as ‘mission’, without sufficient understanding of Eliot’s historical and theological context in the puritan movement and how he applied its ideas to Indian ministry. The thesis examines Eliot’s views on ‘Praying Towns’ as settlements for promoting civility and religion, and ‘Indian churches’ as congregations of true believers formed by covenant (Chapter 4). It investigates Eliot’s activities in the Indian communities, to apply puritan theology and ministerial practice to the Indians as his new parishioners (Chapter 5). Finally, the thesis offers a comparison of puritan and Indian conversion narratives, to try to recover Praying Indians’ own voices about conversion and faith (Chapter 6). This analysis finds both similarities and differences. The extent of the similarities does not necessarily mean (as some have alleged) that puritanism was unilaterally imposed on the Indians. The evidence equally well suggests a nuanced picture of Eliot’s engagement with the Indians from the perspective of 17th century puritanism and its conversion-oriented parish ministry.