Dr. Klein researches the development of notions of “England” as a nation in middle ages, through study of medievals literature ranging from around the world. He also has a continuing interest in the mediation of poetry, from the medievals to the modern -- that is, how is poetry represented on the page and on the screen, and how does the media contribute to the meaning? He has published articles on medievals Anglo-Scottish relations and medievals Anglo-Scandinavian identities, as well as the shifting formal characteristics of medievals English poetry in the tail-rhyme and bob-and-wheel styles.

His current research projects include a monograph on medievals English national identity, Making England, 1200-1500, and a reassessment of editorial habits in editing medievals poetry from their manuscript sources, tentatively titled The Poetics of the Page.