The full significance and influence of the part played by the Prior of the Knights Hospitaller in the middle ages is brought out here in a wide-ranging survey. The Prior of the Knights Hospitaller played a major role not only within the Order, but also in the wider arena of English - and indeed European - politics. This role, and its changes between 1272 and 1540, are the focus of this new book, which draws extensively on archival material both in the United Kingdom and in the Hospitaller archives at Malta. It argues that the Prior's allegiance to the crown was as important as his allegiance to his order, that the relationship between crown and priory was generally cordial and that usually there was no contradiction between service to crown and convent. It demonstrates a general expansion in the public roles of the Hospitaller Prior, not just under the most politically important Priors. It analyses the Priors' interactions with financially important merchants and the terms that three Priors served as treasurers of England. Finally, by revealing how the order lost political control of its estates, it contributes to the broader themes of secularisation and emerging nationalism. Dr SIMON PHILLIPS is a Research Associate of the University of Cyprus and Fellow of the Royal Historical Society.