Trading More than Blows: The Flow of Military Technology Between the Middle Byzantine State and the Islamic Orient

If we are to believe the official statements contained in Byzantine sources (including military manuals, legal texts, and the works of emperors such as Constantine Porphyrogenitus), most aspects of military technology were (or should have been) well-guarded state secrets. Emperor Constantine VII’s advice to his son to protect the “secret” of Greek Fire is a case in point, as are the earlier prohibitions in the Theodosian Code against instructing “barbarians” in the manufacture of weapons and siege engines or exporting shipbuilding techniques to neighbouring nations. Many modern researchers—Byzantinists in particular—have subscribed to this view. But other sources, especially those produced in the Islamic East (a society whose educated elites were far more “mechanically minded” than the Byzantines), paint a different picture: one of the widespread dissemination of military technology and the existence of a common vocabulary of military matters. Our aim is to provide a systematic overview of the current state of research on this fascinating aspect of cultural exchange between the two worlds and to pinpoint gaps in our current knowledge. We also examine the literary sources—both narrative and technical—of the Middle Byzantine period for evidence revealing the degree to which various elements of Byzantine and Arab military technology (technical know-how, terminology, etc.) may have been shared by both powers. We hope this evidence will support the idea that the flow of military technical know-how between the Middle Byzantine state and the Islamic East was not only uninterrupted but also reciprocal. This is a study not only in the history of technology, but in cultural history as well.