Torsion Siege Engine - Historical Continuity

Historical Continuity

There has been some scholarly debate over the use of torsion siege engines. Beginning in the mid-19th century, Guillaume Defour and Louis-Napoléon Bonaparte definitively claimed that torsion siege engines were replaced by trebuchets, tension machines, and counterweight machines early in the Middle Ages because the requisite supplies needed to build the sinew skein and metal support pieces were too difficult to obtain in comparison to the materials needed for tension and counterweight machines. Opposition to this viewpoint appeared later in the 19th century, when General Köhler argued that torsion machines were used throughout the Middle Ages. Scholarly views become more complex at this point, with Rudolf Schneider arguing that the loss of classical knowledge in the early Middle Ages prevented ancient siege engines from being reproduced, while Kalervo Huuri argued that one-armed torsion machines, such as the Roman onager, may have been used in the Medieval Mediterranean, though there was no evidence of two armed machines, such as the ballista, in this view. Much more recently, Randall Rogers and Bernard Bachrach have argued that the lack of evidence regarding torsion siege engines in the Middle Ages does not provide enough proof that they were not used, especially considering that the narrative accounts of these machines almost always do not provide enough information to definitively identify the type of device being described, even with illustrations.

Rogers and Bachrach seem to be the norm today, especially as medieval studies has become less centered on Western Europe. Torsion powered arrow throwers were used throughout the Byzantine Empire at least through the 11th century, and existed in western Europe up through the 14th century as the espringal, as well as in the Muslism World as the ziyar . This is only for two-armed arrow-firing machines, though. Onagers and two-armed stone throwers are still up for modern debate. Konstantin Nossov argues that “beam-sling” stone-throwers that were the pre-cursors of proper trebuchets largely replaced torsion stone-throwers by the 9th century. Tracey Rihill argues that contrary to the literary evidence, one-armed machines predated or at least were concurrent with two-armed machines because they were conceptually and constructionally simpler. Finally, Paul Chevedden avoids the subject entirely, stating that a monograph yet unwritten would be required to make a conclusion one way or the other.