My main interests are the language and literature of the Old and Middle English periods. I have written on a number of works and authors, including Wulfstan of York, The Battle of Maldon, Ancrene Wisse and La3amon’s Brut, as well as texts at the ‘transition’ between Old and Middle English. I am especially interested in contact, diversity and change in early English language and culture, with a focus in particular on Anglo-Scandinavian interactions in the Viking Age and their consequences for the development of English vocabulary. My most recent book is a comprehensive etymological study of the words derived from Old Norse in Sir Gawain and the Green Knight. This forms part of ‘the Gersum Project’, a collaborative project to investigate the Scandinavian influence on northern Middle English alliterative verse.