William Perkins, usually described as an Elizabethan Puritan, was significant in ways that are only beginning to be recognised by historians. His writings, published in numerous editions in England and on the continent and translated into Latin and half a dozen vernacular languages, made him the most prominent English theologian of his day. This article contends that his career was devoted not to bringing about changes in the Established Church but to making that Church's teachings better known and appreciated. Perkins should be seen as a leading apologist for the Elizabethan Church of England.