Martyn Lloyd-Jones (1899–1981) was a Welsh Protestant minister, preacher, and medical doctor. He is best known for his influential preaching and his leadership of Westminster Chapel in London, England, where he served as minister from 1939 to 1968. Lloyd-Jones was a prominent figure within British evangelicalism during the 20th century and played a key role in the Reformed movement within the United Kingdom. His ministry was marked by a strong emphasis on doctrinal purity and the exposition of Scripture, as well as a call for a return to historic Christian orthodoxy and the experience of revival. Lloyd-Jones was deeply critical of liberal theology and the ecumenical movement, advocating instead for a robust evangelical faith based on the doctrines of grace commonly associated with Reformed and Puritan theology. As an author, he produced a large body of work that includes commentaries, sermons, and books on various theological and pastoral subjects. His "Studies in the Sermon on the Mount" and his multi-volume series "Exposition of Ephesians" remain influential among Christians seeking a deeper understanding of the Bible and Reformed theology.