The premise that underpins this detailed and ambitious work is an interesting one that is explored at some depth: that while we are still surrounded by impressive structures that date from Rome, Byzantium and the Middle Ages, we know very little of the men who were directly responsible for their design and construction. Scholars have for many centuries studied the architecture of cathedrals, monasteries, churches, castles, bridges and irrigation systems – subjects which continue to fascinate, be revised and usefully re-examined – but there are few studies of the lives of individual people who achieved what in many cases were audacious, breathtaking technical feats.

Purton begins by considering the evolution of military technology across thirteen centuries from ancient Rome to the Renaissance – an unbroken tradition – and the impact of new technologies in the context of the background of economic and social developments that made them possible. So, this text is a logical and coherent chronological review of events, but not at all confined to Western European traditions. Purton is well travelled over many years and the book covers parallel developments in the Byzantine East and other well-established historic societies and cultures. The period is broken down into seven chapters: ‘Military Engineers in the Middle Ages’; ‘Late Antiquity and the Early “Middle Ages”: Were the “Dark Ages” Really Dark?’ (fourth to the eighth century); ‘Anonymous but Effective: The Engineers and Technicians of the Ninth to the Eleventh Centuries’; ‘The Engineer Recognised’ (eleventh and twelfth centuries); ‘Engineers in Demand: Innovation and Development in the Thirteenth Century’: ‘Old and New Technology and its Operators in the Fourteenth and Early Fifteenth Centuries’; and ‘Polymaths and Specialists in the Fifteenth Century’.

There may have been a case for starting with Greece rather than Rome. One can think of actual, known and well-documented engineer–architects such as Dinocrates (of Rhodes), Phideas, Sostratus and the Athenian Epimachus. Creators, in fact, of some of the Seven Wonders of the World, and better known by name 2,500 years ago than many of the castle builders in Britain from the thirteenth century. Even 1,300 years, however, is a huge span to cover, and there is often so much astonishing detail in The Medieval Military Engineer that any additional depth or detailed analysis, going back yet further in time, could have overloaded a book that is already tightly packed.

Purton’s study is not limited to a strict definition of ‘military engineering’ as such, but covers what today may be called civil engineering projects, that is, roads, canals, dams, hydraulic and irrigation systems and shipbuilding. It should be said that much of the civil engineering has its roots in the need for rapid military-based conquest and control, hence the close relationship with warfare. Nor is the book purely about historical events where warfare technology proved successful (for example, sieges and field campaigns), or technological advances in detail. Rather, it unmasks the often unsung heroes: how the personages involved gradually became known and valued; their sources of education (starting with perhaps with the written texts of Roman Vitruvius and Vegetius – Roman manuals that were never quite lost); their levels of literacy; how their skills were highly valued, even coveted, by emperors, magnates and Renaissance dukes and princes; and how they belatedly received due recognition from those – their wealthy and powerful clients – who in the past had often assumed the credit for the engineers’ works.

With the increased survival of government records from the Middle Ages, engineers (or ingeniators) start to acquire names and individuals begin to be identified and given titles. This is particularly true of the unique records in England and Wales from the twelfth century, especially royal records and the building of castles. On page 6 (n 8), Purton sets out his rationale in relation to his discussion on medieval castles:

This is a point of view with which this reviewer agrees. In fact, British castles do not take up too much of the book’s contents (pp 26, 99–102, 117, 127, 268–9 and 276–8). Purton has been a valued member of the Castle Studies Group for many years and is eminently qualified to discuss this subject. On pages 117 and 127 he briefly outlines the rapid changes in castle-building in Britain, a period when castles still served pre-eminently military roles. Six or seven new significant castle-related developments of the late twelfth and thirteenth centuries are listed on page 127. What remains uncertain is how far the patron was responsible for the results or how far the engineer in charge of the work based it on his own ideas – something that remains virtually unknowable. Sometimes the names of the builders are stated in the Pipe Rolls, but often are not. (Although not stated, it is believed to have been Ailnoth at Orford: Ailnoth seems to be one of the first ingeniators named in the Pipe Rolls from 1158, but a Gaufridus is mentioned in the 31 Henry i volume 1130–1.) In many cases it appears that the innovations introduced in castles by great lords with international experience of warfare, such as William Marshal, were the instigators of much change. It was not the sole preserve of monarchs to initiate change and introduce innovation; however, the names of engineers employed by magnates, rather than the king’s works team, are much harder to source.

In a very welcome appendix (pages 280–4), Purton has extracted and tabulated some of the references to engineers/arbalistarius/master masons by name starting from 1130 and taking the list up to 1230 – from Henry i to Henry iii. These are from the Pipe Rolls of the English Exchequer as translated and published so far (1844–2012, via The Pipe Roll Society). The originals are held at the National Archives. These remain a good source to be mined further as much of the listing refers to those involved in early artillery rather than the full range of ingeniator activities. What it does show is that the earliest engineers appear to have been expected to have the full range of skills (building/carpentry/artillery) with these skills becoming more compartmentalised later. However, at the field campaign level, the siege artillery, siege towers, temporary bridges, earthwork emplacements and underground mines used for war have left little trace; and there is even less known of the engineers – those who were often risking life and limb – behind these military engineering achievements.

The fifteenth century was the age of the great polymaths such as Leonardo da Vinci and Brunelleschi, and saw a new type of literate military engineer, now part of a recognised profession. Vasari’s The Lives of the Artists (several translations available) is the classic work that recounts the development of the Italian Renaissance and the highly inventive solutions and ideas from Giotto (1267–1337) onwards, including architect/engineer polymaths such as Alberti, Michelangelo and Francesco d’Angelo (Il Cecca) (1446–88). But Vasari omits some of the (non-Tuscan) equally talented civil/military engineers whose accomplishments arguably remain more obvious and striking. These include Mariano Taccola of Siena (1382–1458) and the highly accomplished Francesco di Giorgio Martini (1439–1501), also from Siena. The lesser-known work of Taccola, often called the ‘Sienese Archimedes’, stands at the beginning of the tradition of Italian Renaissance artist–engineers, with a growing interest in technological matters of all kinds. Purton rightly devotes several pages to the talents of this often-overlooked early Renaissance polymath, with a discussion on the practical use of gunpowder and other matters. Taccola’s drawings were copied and served as a source of inspiration by those such as Buonacorso Ghiberti (Zibaldone), Francesco di Giorgio and perhaps even Leonardo da Vinci himself.

Purton has carefully scrutinised the Antique, Medieval and Renaissance periods and has been able to isolate many important thoughts, key personnel and significant moments that relate to the achievements of these often-understated polymaths, when only in the fifteenth century did the builder–engineers finally seem to attract as much acclaim and respect as their patrons. In this volume Purton writes with a lucid style and offers us the sound insights and benefits of thirty years of close study, which is relayed to us with methodical clarity and enthusiasm.