The Stirrup Thesis: A transformative technology that wasn’t

By Steven A. Walton

Sometimes there is a story that’s just so simple and explanatory that it just must be true … even when it isn’t. Such is the so-called ‘Stirrup Thesis’ most tightly connected to a story that Lynn White, Jr. told in his 1962 book Medieval Technology and Social Change, which has been one of the few medieval history textbooks to remain continuously in print since its publication.

Put simply – and it is simplistic – the Stirrup Thesis argued that when the Franks discovered the stirrup in the eighth century, they used it to develop a new form of mounted shock combat with the couched lance, made cavalry the dominant military arm and knights the backbone of the military aristocracy (and that then led to a wholesale r/evolution in society to support the horse-owning aristocracy that gets shorthanded in another quasi-mythical concept, ‘feudalism’), and promptly turned back the Umayyad invasion of Gaul from the Iberian Peninsula, thus securing Europe for Christendom.


The problem is, almost all of this is wrong except for Charles Martel winning the Battle of Tours in 732 (also known as the Battle of Poitiers and the Battle of the Highway of the Martyrs by the Arabs). White certainly did overstate his argument, though in his defence, the book is a slim idea piece that, while transformative in using material culture and other then-novel lines of evidence in historic scholarship, may have been more of a trial balloon than it has subsequently become.

In fact, the ideas it proposed became canon, despite reviewers such as Peter Sawyer and then Bernard Bachrach quite clearly demolishing the specifics of the Stirrup Thesis and its overall simplicity (White tried to sustain the argument as late as 1968, when he wrote that “The result is a clear relation between these new means of utilizing the horse and the rapid military, social, and economic changes of the period. And the discussion continues as new evidence accumulates.”). But again, it is the seductive simplicity of the idea that has helped it survive in textbooks to this day.


From the point of view of medieval combat, however, there is still a little life left in the old Stirrup Thesis if we don’t ask it to cause a full-blown, temporally crisp, socio-political revolution in Europe. Indeed, this is beyond the more general ‘horse’ revolution where horses provided strategic and tactical mobility and speed, regardless of whether the warriors then fought on horseback as heavy cavalry, used their speed to harass as light cavalry, or even dismounted to fight as infantry. White wrote that:

the stirrup, by giving lateral support in addition to the front and back support offered by pommel and cantle, effectively welded horse and rider into a single fighting unit capable of a violence without precedent. The fighter’s hand no longer delivered the blow: it merely guided it.

It is true that his recognition of the development of shock combat has some value to it, but that development is a slow one. Stirrups did appear in Europe in the seventh (or perhaps the sixth) century, and along with associated saddle furniture they continued to develop over the next couple of centuries. Different groups adopted them to a greater or lesser degree in combat. In some places, well into the eleventh century, ‘cavalry actions’, doubtless using stirrups by that time, used their horses to manoeuvre but then still chose to dismount to fight. So it certainly looks like evolution more than revolution in this case, and the effect may have been still more pronounced in creating the social rather than strictly military role of the chevalier and the courtly code we now know as ‘chivalry’ (also perhaps overblown and romanticized, but that is for another article).

Cover of the 1978 edition of Medieval Technology and Social Change

There are two difficulties in accepting the larger Stirrup Thesis, or for that matter any argument that sees new technology as transformative. First is the question of causation and whether a new technology just makes other new things – such as social organization, patterns of behaviour, or power structures – inevitable or merely possible. As White would in fact say in the book, a new technology “merely opens a door, it does not compel one to enter” (though in other places he speaks of things happening “inevitably” and did specifically say the stirrup had a “catalytic influence on history”).


Further, there is a question of the relative advantage between various technological systems. It would appear, as Stephen Morillo has argued, that the rise of cavalry in the later first millennium has less to do with any specific advantages of that military arm – technological or otherwise – but rather that in this period there was not as much capability to recruit and especially train infantry to a high degree of professionalism. So whether or not knights had stirrups or better saddles is partly moot if they were the main fighting force who were practiced in the art of war, in or out of the saddle.

A revolution when?

The other problem is that of chronology. On the one hand, a new technology may appear in a culture and not cause any appreciable change for a considerable time; on the other, a social change might occur, as it turns out, before the technology arrives, in which case the technology gets fit into an existing social context, rather than creating it. So in this case, the stirrup was used by the Anglo-Saxons and Germanic tribes well before the Franks – and by the Indians and Chinese well before that – and yet it caused no revolution and they fought dismounted. For that matter, it now appears that while linguistic evidence places stirrups in Western Europe well before the eighth century, the Franks actually started using stirrups widely only well after the momentous turning-back of the Umayyads at Tours. Oh, and at that battle, the Arab sources note that the Franks fought on foot, more or less in a phalanx, in order to blunt the Muslims’ cavalry superiority!

Further, the Carolingians who discovered this supposedly ‘transformative technology’ in warfare then don’t seem to have relied on heavy cavalry for much at all for the next century and more. In fact, mounted shock combat as a relatively decisive practice did not become that common in Europe until the twelfth century, four centuries after White thought he saw it changing everything. And even worse, there was an ‘Infantry Revolution’, which did not rely on any new technologies, shortly after that, which blunted the cavalry advantage quite effectively until the arrival of gunpowder changed things again.

The flaring sides of this stirrup, dating to the 8th or 9th century. It was found in Northern Poland, are decorated with bands inlaid in silver bearing geometrical designs along the edges, and are pierced with a series of triangular openings. Photo coutesy The Metropolitan Museum of Art

But back in the case of the stirrup, changes ascribed to a new technology may in fact have started before the technology appeared in that culture: in this case changes in agrarian practices, land ownership, social structure, and lordship can be seen, variably, before and after this one ‘simple’ invention. Much like White’s similar idea of a ‘medieval industrial revolution’, historians are now more and more aware of the continuity of technologies from the ancient through the medieval world, and of ‘feudalism’, if such ever really existed as a pure concept, as a gradual evolution spanning the medieval centuries.

Finally, on a very concrete note, in 2016 Alan Williams, David Edge, and Tobias Capwell made an experimental trial of how much force a rider with and without stirrups could deliver. They did find that stirrups gave a very modest increase of less than 30% – they qualify it as ‘insignificant’ – over a rider without them. However, and much more importantly, they found the stirrup advantage was insignificant compared to the developments in war saddles and especially lance rests and stops by the fifteenth century, which doubled the energy delivered to the target. So if we follow the logic of the Stirrup Thesis and correlate it with some quantitative data, we would be forced to accept the idea that a modest performance increase with the stirrup is thought to have precipitated a revolution, but a demonstrable increase from the saddle apparently did not.

It’s therefore long past time to retire the Stirrup Thesis once and for all, but its stubborn persistence demonstrates how hard our modern world seems to want to believe in that ‘one key technology’ that makes all the difference. It’s rarely there, and even if it seems to be, it’s always much more complex than that. But we seem to want such simplicity, even in warfare where it’s never that way.

Steven A. Walton is Associate Professor of History at Michigan Technological University. He is also the Editor-in-Chief for the journal Vulcan: The Journal for the History of Military Technology. Click here to view his university webpage.


Further Readings:

Bachrach, Bernard S., “Charles Martel, Mounted Shock Combat, the Stirrup, and Feudalism,” Studies in Medieval and Renaissance History 7 (1970): 49–75.

DeVries, Kelly and Robert Douglas Smith, Medieval Military Technology, 2nd ed. (University of Toronto Press, 2012), 99–114.

Morillo, Stephen, Warfare under the Anglo-Norman Kings (Boydell, 1997), 150-162.

Roland, Alex, ‘Once More into the Stirrups: Lynn White, Jr., Medieval Technology and Social Change’, Technology and Culture 44, no. 3 (2003): 574–585.

Sawyer, P. H. and Hilton, R. H., “Technical Determinism: The Stirrup and the Plough,” Past and Present 24 (April 1963): 90–100.

Williams, Alan, David Edge, and Tobias Capwell, “An Experimental Investigation of Late Medieval Combat with the Couched Lance,” Journal of the Arms and Armour Society 22:1 (2016): 1–16.

This article was first published in Medieval Warfare magazine. Click here to buy that issue.

Top Image: Knights appreciated the advantage of having stirrups when it came to doing battle with dangerous foes. Image: British Library MS Yates Thompson 19  fol. 65r