This thesis identifies how the early medieval Church developed in Somerset; the relevant date range being from the post-Roman period, or the mid-seventh century in Somerset, to the eleventh century. The key objective of the thesis being to use Somerset as a case study in order to contribute to a wider understanding of how the early Church evolved across the British Isles. It achieves this by developing a systematic, multi-disciplinary approach using a broad range of data including for example, archaeological, historical and topographical evidence. Whereas the starting point for previous research into the early Church was the known or probable minster churches, this thesis uses an inclusive approach so that the starting point is a list of every pre-sixteenth-century church and chapel in Somerset. Adopting this approach has ensured that any early medieval minsters which lost significance over time have been identified. Without this approach it would have been impossible to understand how the Church developed. A major issue to be faced in understanding Church development in Somerset is the paucity of historical, architectural and archaeological evidence. This thesis therefore focuses on identifying the early great estates and how they divided into the early parochiae and shows that by building on the work of other researchers it is possible to use topographical evidence to identify early great estate and parochiae boundaries. The topographical evidence, coupled with historical and morphological data also facilitated the development of criteria to identify when sites were chosen as religious focal points including the sites of Somerset's post-Roman churches. This then made it possible to establish the principles and criteria by which Somerset's early medieval parochial minsters can be identified and how the evolving structure of the early Church in the county and across the South-West can be understood.