Michael Daniel Jones (1822-1898) is regarded as a pioneering figure in nineteenthcentury Wales. He has been hailed not only as the `father' of the Welsh Settlement that was established in Patagonia in 1865, but also as the `founding father of modem Welsh nationalism'. As Congregational minister and principal of the Independent College in Bala, Jones also played a leading role in a widely publicized dispute concerning the future of Congregationalism in Wales. Despite this acclaim, Michael D. Jones has been the subject of remarkably little study. Apart from a biography, published in 1903, only a handful of articles have been written on him. Though these studies have shed some light on Jones's contribution to nineteenth-century Wales, they have not offered a portrayal that takes into account all aspects of his work and thought. Based on thorough examination of all the available sources, this study is a reevaluation of Michael D. Jones's life, work and thought. Four primary aspects of his thought - religion, radicalism, identity and nationalism - are analysed carefully in order to clarify his views and to place them within the broader context of nineteenthcentury Wales. This is followed by an examination of Jones's participation in various spheres, in particular his role in the formation of a Welsh Settlement (1856-1865), his involvement in the dispute at Bala College (1855-1892), his relationship with the Patagonian Settlement (1865-1892), and his contribution to the `national awakening' in Wales (1876-1892). The details that emerge provide a clearer understanding of the life, work and thought of Michael D. Jones, and challenge some of the conclusions that have been drawn on the basis of less extensive studies.