Engineering Analysis of Siege Engines in the First Crusade

—Ian Lindberg (Mentor: David Bachrach)
Lindberg Homepage Photo

The First Crusade, considered by most scholars to have begun in 1096 and concluded by 1099, was a war of conquest waged by several European armies with the goal of taking over the Levant, known to them as the Holy Land, from its Muslim inhabitants. Throughout the course of the Crusade, pivotal military encounters took place in the form of sieges rather than pitched battles. This was a critical period in medieval history, and this military campaign has long been analyzed by historians (Asbridge). However, there has never been an engineering analysis of the siege engines, machines designed to assist in capturing fortifications, used during the crusade. Understanding the siege engines that were crucial to Crusader victories is necessary to understanding the campaign as a whole.

During the summer of 2022, I set out to research these siege engines with the support of a Summer Undergraduate Research Fellowship (SURF). To make an accurate assessment, I needed to analyze them from an engineering perspective, as siege engines can be viewed as a kind of machine, limited by all the same engineering and physics principles as any modern machine would be today. As someone pursuing a major in mechanical engineering and a minor in history, I was ideally suited to interpreting the descriptions of siege engines as presented in historical texts. The ultimate goal of this research was to identify siege engines from historical texts, create plausible designs for them, then turn these designs and the justification for them into a form useful for historians studying this period.  At the time of the writing of this research article, I have been able to use the descriptions provided in the sources along with supplementary materials, including academic papers, to create a 3D model of a siege tower. By using engineering methods and software, I was able to make this model both accurate to descriptions provided in sources as well as capable of being used in the manner described in the sources.

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