This dissertation attempts to chart the history of the English-speaking churches of North Wales from the time of the commonwealth to the present. Beginning with the radical separatism of Morgan Llwyd at Wrexham during the puritan period, it describes and analyzes the development of religious thought and structures through the restoration and the older dissent (chapter one), the eighteenth century including the Evangelical Revival and Sandemanianism (chapter two), the expansion of the churches including those on the coastal strip during the nineteenth century (chapters three and four) and consolidation including the challenges of secularization during the twentieth (chapters five and six). The Introduction sets out the rationale and the Conclusion provides a reflective summary. Thee essential elements form the parameters within which the following analysis has been made, namely geography, language and the Baptist principle of associating. The way in which an English medium community formulated its religious identity within a Welsh, and often Welsh speaking, context is assessed, and how it did so well away from the very different English language Baptist life in South Wales while diverging also from mainstream Baptist life in England. As such the dissertation could be interpreted as a study in divergence, assimilation and the development of a specific regional-national identity. The backcloth for the individual chapters is determined by United Kingdomwide or British, national (Welsh), or denominational topicalities each of which may stand alone or exist in combination with the others. In broad terms the formative years are dominated by British considerations, national (Welsh) factors predominate during the nineteenth century, whilst the twentieth century is dominated by denominational concerns. Throughout the study the three formative factors of geography, language and the specifically Baptist principle of associating emerge as the key elements in the evolution of the English-speaking Baptist churches and the North Wales English Baptist Union.