Reviewed by: The Medieval Military Engineer: From the Roman Empire to the Sixteenth Century by Peter Purton Susan Broomhall Purton, Peter, The Medieval Military Engineer: From the Roman Empire to the Sixteenth Century (Armour and Weapons), Woodbridge, The Boydell Press, 2018; hardback; pp. xiv, 351; 30 b/w illustrations; R.R.P. £60.00; ISBN 9781783272875. As its title suggests, the ambition of this work is to focus on the changing experiences and status of the military engineer in the Middle Ages. Warfare made these individuals important skilled workers: indeed, critical assets for leaders. This does not mean, for the most past, tracing who these workers were and what they did, but rather what kind of people they must have been, the skills that they would have required, and the varied transmission pathways by which they could acquire such knowledge. Peter Purton traces a continuous, evolving corpus of professional and technical knowledge across the period, assessing the impact of new forms of warfare—from the introduction of mobile siege towers to gunpowder—on the practitioner and the skills that these demanded. The time period covered here as 'medieval' extends from late antiquity to the early sixteenth century with Leonardo da Vinci. The earlier period has a relative deficit of direct sources for this subject, and Purton thus pulls together written sources, archaeological material and visual evidence from many social levels. He is interested in what might be revealed about these workers, not just in the employ of rulers but also that of noblemen, bishops and other kinds of leading officials who were also responsible for warfare or defence. Purton's investigations span Christian Europe in interaction with the Islamic world, with brief investigations into the activities of the Mongol empire and Chinese technologies that impacted Europe. As might thus be expected, there is no consistent terminology for such workers, as they change skillsets and significance across the period, and in the context of varied kinds of documents in which references to their work appears. The word 'engineer', which combines both the functional making of engines and machines and the creative, in the sense of ingenuity, is employed in the title and throughout the work as an acknowledged shorthand for a group of skilled men in varied roles and of different status, who would not necessarily have identified with this term. It is difficult to sustain any clear distinction between civil and military engineering and thus Purton's subject ranges across land reclamation, hydraulic engineering, dams, canals, and ship building, as well as more familiar military technologies such as the trebuchet. For the earlier periods, there are fewer names and more conjecture from archaeological evidence about the skills and knowledge that must have been needed to exploit advanced technologies such as irrigation, bridge-building, geometry (for laying an encampment), as well as arms manufacture. Individuals start to emerge from the records more consistently by the twelfth century, as payment records provide details of who such men were, how they were paid, and for what appear to be increasingly specialized technologies. By the thirteenth century, there are growing references to military technology in advice to rulers, but far less is said about the men who were needed to make [End Page 238] and maintain it. Account records, though, suggest that there are more of such men and performing more specialized roles. With the introduction of gunpowder and new artillery forms in the Christian and Muslim worlds by the fourteenth century, designated gun masters emerge among the named individuals whose careers can be fleshed out to some extent. In the fifteenth century, increased literacy assisted the production of practically oriented manuals and the advent of the expert master-author such as Jörg of Nürnberg, papal gun master, who left his own account by which something of a professional career can be constructed. Purton concludes that the fifteenth and sixteenth centuries are marked by moves towards ever more defined specialisms, making famous polymaths such as Leonardo outliers to the broader trend. The work concludes with an appendix of military engineers and miners listed in the Pipe Rolls of the English Exchequer, showing something of Purton's methodology for identification, and a useful...