In his biography of Archbishop William Courtenay published in 1966, Joseph Dahmus wrote that ‘until documented evidence to the contrary is provided, one may assume that the connection between Wycliffitism at Oxford and Lollardy was hardly more than accidental. Although the work of Anne Hudson and Michael Wilks has since shown that the link was anything but accidental, Dahmus’ scepticism is I am grateful to the participants in the three seminars at which this paper was read for their comments, and especially to Dr J. R. L. Highfield and Dr Paul Brand, both of whom offered helpful suggestions for its improvement. All remaining errors are my own. I thank also the Warden and fellows of Merton College, for allowing me access to their splendid archive, and Mr John Burgass, former assistant librarian, his successor Mrs Fiona Wilkes, Dr S. J. Gunn, and Dr Sarah Bendall for their assistance.