He teaches and researches the history of late medieval and early modern Britain and Europe, and is the author of a number of academic texts.
[5] Gunn's research interests lie in the political, social, cultural and military history of England and its European neighbours, spanning the mid-fifteenth to the late sixteenth century.
[7] Gunn delivered the 2015 James Ford Lectures in British History at the University of Oxford, taking as his subject 'The English people at war in the age of Henry VIII'.
[8] Between 2018 and 2019 Gunn served as Acting Warden of Merton College in the period between the retirement of Martin J. Taylor and the arrival of his successor, Irene Tracey.
[10] In 2021 Gunn was appointed to the board of trustees of the Royal Armouries by Oliver Dowden, the Secretary of State for Digital, Culture, Media and Sport, serving a four-year term.