Book excerpt: This is the most complete account yet of Lollardy, the medieval English heretical movement derived from the ideas of John Wyclif that anticipated many of the ideas and demands of sixteenth- and seventeenth-century reformers and Puritans. Considering new evidence--such as texts composed or assembled by adherents of Lollardy, episcopal records, chronicles, and tracts written against Wyclif and his followers--Hudson offers an exceptionally coherent picture of the movement, sheds new light on the reasoning that lay behind the radical opinions of Wyclif's disciples, and demonstrates that the concern shown by ecclesiastical authorities may have been justified.