The reform movement known variously as Wycliffism or Lollardy is now a familiar feature of the premodern intellectual and religious landscape. But even though "heresy" has migrated to the forefront of medieval studies in recent decades, Wycliffite biblical scholarship itself has escaped sustained attention, especially its different tiers of textual form and practice. This book examines Wycliffism as it moves from late scholastic discourses of academic biblical study to the material contexts of English book and manuscript production. This shift, though often adduced to explain the rise of popular heresy, also exposed changing paradigms in the history of late medieval writing and religious culture. The author argues that ambitious assemblages of translation and commentary reframed ideological definitions of scriptural authority and revised established views about the bible as a book.