Byzantines, Avars and the Introduction of the Trebuchet
By Stephen McCotter
Published Online (2003)
Introduction: While there has been much debate over when the traction trebuchet appeared in the west and the extent to which it replaced late-antique torsion weapons there, its appearance in eastern Europe and the Mediterranean has attracted less attention. This cannot afford to be passed over without comment, especially given its implications for later military development, as the trebuchet, in its various forms, was the mainstay of medieval siege artillery until the development of effective cannon. Some earlier historians such as Hurri reckoned that the trebuchet came to western Europe when the first crusaders returned home at the close of the eleventh century. However this view was challenged in the 1970s when Donald Hill asserted that the route of transmission was almost certainly through the Arabs, a theory supported by Carroll Gillmor. This view ignores evidence in the seventh-century Miracles of St Demetrios which brings the Byzantines and Avars into the picture, as recognised by James Howard-Johnson and Paul Chevedden. Sometime in the late sixth or early seventh century this form of lever artillery began to appear in the Byzantine empire, probably spreading from China. Were the Avars, a nomadic people from the steppes, the means of its dissemination to the Byzantines, and, if so, how quickly did the Byzantines, and possibly the Persians, copy this weapon? The introduction of the traction trebuchet is a very difficult issue to resolve owing to a lack of clear source material and the question is still open to much debate. This paper does not set out to draw any definitive conclusions; rather its purpose is to reopen discussion on the topic through the introduction of new elements to the equation.
The adoption of the early traction trebuchet is an interesting example of technology transfer. Our main source for its introduction comes from the Miracles of St Demetrios where they describe the Avar siege of Thessalonica. The bishop who penned the miracles, John, compares the inaccurate rope-pulled devices of the Avars with the accuracy of the Byzantine torsion artillery. This is most interesting as it shows that the Avar weapons were noticeably different from the Byzantine ones. The bishop gives the following description:
‘….they were four-sided; they rose from broader bases to narrower tops on which there were massive cylinders, their ends sheathed with a thick layer of iron; to them there were attached lengths of wood, like the beams of a large house, and these had slings; and when these (the slings) were raised up, they sent out rocks; the rocks were large, the shots frequent…’
This is clearly a description of a trebuchet and compares well with pictures in medieval manuscripts, apart from the fact that the men pulling on ropes, the propellant of the traction trebuchet, seem at first to have escaped the bishop’s observation. However, they may well have been obscured from his view by the sheaths of iron, or probably more commonly leather, which could have been used as protection for the otherwise exposed crew members. It is likely that the trebuchet was introduced from the east around this point in time, and the Avars could well have been the means of its transmission from China where it had been in service since the third century BC.