Military Technology in the writings of John of Salisbury
By John Hosler
Technology and Warfare: 38th International Congress of Military History Proceedings (2012)
Introduction: The 2011 Weapons System Handbook, accessible online, provides a ready guide to non-classified ammunition, weapons, vehicles, intelligence and control equipment, and a host of other current military technologies used by the United States Army. In over three hundred pages it not only provides the Army’s official terminology for these devices but also their dimensions, capabilities, and applications. Medieval military historians can only dream of such detailed, government-approved, technical sources. Outright descriptions of military materials are rare in the Middle Ages, which was an era without standing armies or military-industrial complexes. Medievalists also face another peculiar challenge: the extant sources for military affairs were often written by ecclesiastics who were relatively ignorant of troop-types, tactics, and military technology. As a result, modern interpretation of medieval campaigns hinges on language that is often imprecise, misleading, or wholly incorrect.
I have lately written a book on one of the major ecclesiastical sources for warfare in the twelfth century, John of Salisbury. John was one of the best-educated men of his day and worked as a clerk to the archbishops of Canterbury; later in life, he became the treasurer of Exeter Cathedral and also the bishop of Chartres. John was a prolific author who wrote three major books, two saints’ lives, two moralistic poems, and 325 personal letters. Of these works, undoubtedly the most famous is the treatise Policraticus, which was heavily read in the later Middle Ages and remains on many university political science reading lists today.
In the course of my research, I endeavored to catalog every technological military term John of Salisbury used across his entire corpus: every word for arms, armor, equipment, and transportation. The result is a collection of over six hundred Latin terms that, on face value, constitutes an important resource for military historians. Yet caution is needed because John neither participated in combat nor witnessed an actual battle with his own eyes, and much of his terminology came not from contemporary sources but rather from a sizable array of Biblical and ancient texts in his library. Before properly assessing John’s contribution to the study of 72 medieval warfare one must first come to grips with his military language. The precision or vagueness of his word choices often affects the reliability of his military descriptions and, therefore, the utility of his writings for military historians.
It is my argument that John of Salisbury’s soundness as a source for medieval military technology is a provable notion. To do this, I will first explain my method of checking the accuracy of his terminology. Then, I will demonstrate the extent to which his descriptions of arms and armor mesh well with the military customs of his own day. Finally, I will offer some thoughts on the applicability of my method to other medieval, ecclesiastical sources.