Historian specialising in the Napoleonic Wars and Tutor at the Department for Continuing Education, University of Oxford.

He has written numerous books and papers on matters relating to the Napoleonic wars. His first book, An Atlas and Concise Military History of the Peninsular War was published in 2010 and was selected as the Daily Telegraph (History) Book of the Year.

He is recognised as a world authority on the battles and battlefields of the Iberian Peninsula and Southern France.