John Trevisa is one of the best documented of late medieval extraclergial writers. We know just when Trevisa was at Oxford, and which colleges he belonged to; we even know which books disappeared with him and a group of colleagues when they were expelled from Queen's. We know roughly what years he was vicar of Berkeley. We know that the patron who financed the production of most of his work was Thomas Berkeley – and Hanna's work on Berkeley has helped to show why this relationship was a remarkably productive one – and we have ample record in manuscript of the six translations and two short original works Trevisa is known to have produced. So attractive is this fund of information about one particular education and relationship of patronage that there have been a number of attempts to assign to Trevisa other anonymous but now much better known late medieval English works whose sentiments and concerns resemble those expressed in works we can be confident in assigning to Trevisa. Thus, it has been suggested that Trevisa was the author of the revisions of Piers Plowman, and that he either translated the bible into English on his own or participated in the Wycliffite translation. Rather than an attempt to advance those claims, my reason for beginning with Trevisa is that his well documented position helps to show why the sentiments and concerns he shares with the author of Piers Plowman and later Wycliffite writers were of broad interest, and how they became so controversial.