The military literature available to the Middle Ages was dominated by two classical texts, the Strategemata of Frontinus, compiled late in the first century, and the De re militari of Vegetius, written some time in the late fourth or early fifth century. Of these, the more significant was undoubtedly the work of Vegetius, whose influence developed steadily (and not always in a narrow, military direction) as time progressed. That, however, is no reason for ignoring Frontinus, the importance of whose work Vegetius himself acknowledged in fulsome terms, and which was to bequeath the medieval world a seam of exempla from which to mine information and ideas regarding military practice in the classical past which might be useful to later ages.

The career of Sextus Julius Frontinus (c. 35–103 AD) was one of public service, both civil and military. The holder of high office in Rome under a number of emperors, he also served in the army in Germany and in Britain, where he was governor from c. 76 to c. 78 AD. His practical experience as Rome's water commissioner was reflected in De aquis urbis Romae, which describes the system of aqueducts bringing water to the city, and, written some years earlier, a work on military science, now lost, to which the Strategemata, composed after 84 AD, provided the evidence of stratagems taken from ‘utraque lingua’, ‘both languages’, Greek as well as Latin.

It is this work whose fortune and significance this essay will attempt to trace. In an introductory statement, Frontinus told his readers how it came into being. He had, he explained, already written a work on military science (res militaris), reducing its practices to a system. However, he felt the need to provide a complementary work, which would supply examples of the teachings and recommendations to which he had given prominence in his lost work.