Cavalry: Improved Model

The previous section served to introduce the cavalry and present a very general overview of how cavalry action. At the conclusion of the first sequence of models the difficulties of developing a good model became apparent. This section will go back to some of the basic ideas and try to develop a somewhat improved model

The "Turma" in motion

"Turma" is a term to describe the imperial sub-unit; it is used here in a looser sense to simply identify the small group of about 30 tribal cavalrymen around which the models are based. Its use does not imply that these men were organized as a formal turma.

In frames 2, 3 and 4 the cavalry trotted 75 feet at an average speed of 9 mph. It then galloped 150 feet at an average speed of 13 mph and charged the final 75 feet at 22 mph. The variations for each of the gaits is trot: 7-13 mph; easy gallop: 9-18 mph, all out gallop: 15-28. Following a general distribution curve, about 2/3 of the horses would fall close to the average with 1/6 on either extreme.

Using this data the chart on the left shows the miles per hour for each of the three gaits. In the lower part the times that each gait is used is shown on the right side with the distances in feet that slow, average and fast horses would cover in the allotted time. At the very bottom are the cumulative distances the horses would have covered.

The variation is extreme, probably more than would have happened in reality. For one thing, those on very fast horses would not necessarily have ridden at their top speed, preferring, rather, to stay closer to the group for support. At the trot and easy gallop gaits the slower horses may have had some ability to keep up.

What is noteworthy is the difference between the average and the slowest horses at a full gallop over a mere 75 feet.

For modeling purposes the horses will be shown nearly in a line at the conclusion of the trotting phase, under the assumption that the lines could be relatively well maintained at this pace. During the 150 feet of the easy gallop the variations in distance will begin to show up but will not be shown as large as those the chart might predict. The fastest horses will be held to 170 feet distance covered (down from the 209 shown on the chart) and the slowest horses will be considered to have run closer to their fastest speeds and therefore to have covered at least 135 feet (up from the 104 shown on the chart). During the full gallop phase the difference between slow and average will be maintained but the fastest horses will be held back to 85 feet distance covered (down from the 94 feet shown on the chart). The positions at the end of each phase are illustrated below. The left box shows the relative positions of the ten horses in the first rank at the conclusion of the trotting phase, the middle box shows them after the easy gallop phase and the final box shows where they would be after the fast gallop phase.

The box on the left is 18 feet deep; in the middle, 32 feet; and on the right, 46 feet. These positions are based on the chart and adjustments to it described above. When visualized this way the variations seem too great in the final box. Those in the middle box look much more credible. However,appearances may be deceiving, the data on horses would certainly seem to support the variations shown in the illustration. If there were less variation it could be attributed to those on faster horses reining in their mounts to maintain a tighter formation.

If one were to add in the second and third ranks of the turma formation then the spread would be quite large, indeed. Even if there were no space left intentionally between the ranks the natural spacing of the horses and differences in their gaits would inevitably spread the formation out. Taking the images above and placing two more lines of horses behind them and distributing the fast and slow horses randomly among the files gives the following:



The boxes are 47 feet, 64 feet and 71 feet deep respectively. These positions follow those derived from the chart. In each rank the fast and slow horses were distributed randomly and then allowed to move forward either the maximum distances for the type of horse or until they came up on the horse in front. This actually gives a fairly tight grouping as the slower horses tend to create bunching up behind them. The final formations are not far off from what intuitively "looks" right.

While no one can observe an actual cavalry battle, galloping horses can be watched racing on television. The genetic variations between the highly bred race-horses should be less than that between ancient cavalry mounts. Yet, even among the top horses in the world, the variations in speed are apparent within just a few strides. Many horse lengths separate the leaders from those at the back by even the first turn on the track. How much more variation there must have been among the horses available to the Romans and their allies. The model above is probably well within reasonable bounds.

Freewheeling Turmae

By all descriptions, cavalry clashes should be fluid. One side is said to have often turned and fled before contact was made; to be pursued by the other side. Often the roles might be reversed, perhaps by the intervention of reserve lines or because horses tired. The challenge is to develop a model that credibly allows for that type of mobility.

The main problem is in allowing the horses the opportunity to wheel about. Cavalry could number in the thousands. Without a doubt the formations had to have been many hundreds of riders wide. Clearly, the necessary mobility could hardly come from the entire formation turning. If a line of 200 horsemen turned to the right the resulting line, nose to tail, would be 1,600 feet long (8 feet to the horse, minimum). Such a line, even if it could turn and maneuver in unison (which it could not, of course) would be far too unwieldy to offer the kind of mobility necessary.

Therefore, if the cavalry is to be able to wheel about and run away then it must be done by smaller units either turning in on themselves or wheeling through gaps between themselves and adjacent units.

Horses can turn in fairly tight circles, as American barrel racing proves. In the case of the cavalry, the preferred turn would almost certainly be to the rider's right to take advantage of the protection of his shield. Turning is not the problem. Avoiding a collision with horses to the side or back is.

The only visualization of cavalry action we have these days is through the medium of the movies. While Hollywood is notoriously inaccurate when it comes to any sort of historical detail, still there is valuable information encoded in the movies. In the second of the Lord of the Rings movies, The Two Towers, there is a scene where the riders of the Mark meet the three heros. A group of, perhaps, 100 riders trotting in loose formation rides just past the three when they are hailed. As a group they wheel about to face the newcomers behind them. The turning motion is instructive. This relatively small cavalry force turns in a circle with a radius roughly equal to the width of the formation. This reinforces the conclusions reached above -- cavalry cannot readily turn in on itself but must wheel through arcs the size of the formation itself.

Running away before contact

It is said that many, perhaps most, cavalry skirmishes never involved any actual contact. One side would turn tail and run before ever making actual contact with the enemy force.

Could the decision to turn and run be the result of a command decision? It would seem unlikely. The noise of the hooves would almost certainly drown out any signal. Rather, it would seem that each small group would decide for itself, perhaps following the lead of the boldest, most forward man.

How much time would the turma have to decide to run away and make the maneuver?

This illustration shows the elongated boxes that fit the more spread out turmae as described above. The first two boxes, red and blue, are 50 yards apart, the distance at which the fast gallop would begin for both sides. Each column of boxes shows the relative positions of the two cavalry forces in one second intervals. At the fast gallop about 22 miles per hour (32.3 ft. per sec.), the two sides would meet in just over two seconds. The final three red boxes show that the red cavalry would overrun the initial blue cavalry positions in about 5 seconds.

That means that if the blue cavalry is to turn and run away it would almost have to do it at this distance. Five seconds would be very little time for a large block of men to spontaneously decide that they did not wish to engage the enemy, wheel their horses about, and escape.

A tribal cavalry unit of 600 men, arranged 3 deep and 200 horses wide, 4 ft. to the horse, would extend about 800 feet, over two American football fields. How long would it take for a spontaneous decision to run away to get communicated along this line of galloping men? The 200 man width would represent 20 of these 10-man wide turma formations. If several turmae in the middle of the line wheeled around those next to them could follow suit within a few seconds. This would have to be repeated by the next set on either side and then once more for all 10 turmae to react. It could hardly take less than one second for each turma to notice that the one next to it had begun to stop and turn, another second for it to follow suit. Two seconds per turma, repeated 4 times as the ripple effect extended from the center turma to those and the two edges. 8 seconds for the tribal unit to react. At least.

In 8 seconds a horse galloping at a moderate pace of 15 mph would cover 176 feet. A cavalry unit at full gallop (22 mph) could cover 258 feet. Seeing the enemy turn to flee would urge the soldiers to pursue at the utmost speed, so that the faster speed and greater distances would be more likely than the slower speed chase.

That means that cavalry engagements in which one side turned and rode away before any contact could be made were long range affairs. One side would have had to begin its turn-about at well over 200 feet away.

In this type of action the soldier would have time to bring his horse to a halt, turn it about on its own length, and gallop away in the other direction.

Limited contact then retreat

Another type of action is also described. If neither side turns tail then the two forces meet. But, as observers noted, not at a gallop but at a slow pace, a walk, or even stopped altogether. This model would have the two sides galloping at each other until they were quite close then coming to a virtual stop some slight distance apart. Some skirmishing with spears may follow, thrusting but not throwing. (As noted earlier, no descriptions of the Celtic cavalry of the late republican era describe them as carrying more than one spear. One spear is a thrusting weapon and would only be thrown as a last resort. Swords, when used, would have been a secondary weapon, not having anything like the reach of a spear thrust.) After some time one side become intimidated, turns and leaves the field, probably chased by the enemy.


This drawing attempts to show a highly imaginary view of a cavalry encounter in four stages. Reading from left to right, the two cavalry units are about to make contact. As both realize that no one is turning and running away they slow down, second box, to a walk. The lines stop or nearly stop some short distance from each other. The unit closes up on itself. In box three the two sides make contact with each other in a light skirmishing manner. A few braver soldiers edge out ahead of the main unit and engage individual enemies. And, in box 4, one unit turns in on itself and runs away. The enemy would pursue but is not shown doing so because it would be too confusing to illustrate it that way.

The fighting is with thrusting spears. Swords, presumably used when the spear broke or had to be thrown, had a much shorter range. One soldier, toward the right side, is shown with a sword.

Intermingled lines

There is some evidence that cavalrymen literally mixed it up. The design of the imperial cavalry helmet provided additional protection to the neck and sides of the head, seeming to imply that the soldier might expect to be attacked from those directions(Goldsworthy, P. 237). This type of encounter is somewhat easier to imagine since Hollywood movies have so often shown just this sort of battle. What would be difficult for us to comprehend is the horror, the confusion, even the noise of it all. In the previous section I quoted the account of a cavalry officer in the Battle of Balaclava. It bears repeating: "I can't say I saw the man who hit me, we were all in a crowd cutting and hacking at each other, and I did not know till some time after that I was touched when my wrist got stiff, then I found the cut through my coat, it was only bruised for a few days ... The wounds our long swords made were terrible, heads nearly cut off apparently at a stroke, and a great number must have died who got away. Our corporal who was killed was nearly cut to pieces, his left arm nearly severed in four places ... All of the Russians seem to cut at the let wrist, so many men lost fingers and got their hands cut."

A mix of events

Of course, along an extended cavalry front there was virtually no possibility that everything would be coordinated. In some places one side might turn and run quite far from the enemy, at others the two sides may engage in light skirmishing and in still others they could be fully intermingled in fierce hand-to-hand combat. It might now be possible to create a slightly better model than the first attempt.

Frame 2: Revised: The starting position

This illustration was the previous frame two position, showing the armies 450 feet apart, at the point where the cavalry charge would begin.







For this model the focus will be on the cavalry units in the circled area. A close-up view of that area is shown at the left.


The two sides are about 450 feet (150 yards) apart. The second line of the red army is 100 feet behind the first, the second line of the blue army is 150 feet back.




In the paragraphs above the chart showing the gaits of horses and miles per hour was modified for modeling purposes. The new chart on the left summarizes the data. The speed of the average horse has a yellow background, that of the fastest horses has rose and that of the slowest has green. The data from the previous chart is in blue text font, the data to be used in the models is in red text font.

Nothing is listed in this chart for fast or slow horses during the trotting phase since the units are presumed to be able to maintain their ranks and files at this pace.

The RANGE column gives the distance between the two armies as the gait it begun, the FT column shows how far the unit moves using that gait, MPH and FT/SEC are self explanatory, the SEC column shows how long it takes for the average horses to cover the required distances. The faster and slower horses have the same number of seconds so they travel different distances.

The actual speed and distance the turma travels will tend more toward the average or even the slower speeds. The more ranks the formation has the greater the likelihood that there will be a slow horse somewhere in any given file. Since passing is not allowed, all of the horses behind the slow horse must match his pace. As elements of the unit are forced into the slower pace the leading elements would need to rein in their mounts so that they do not get too far ahead and become isolated.

The chart above provides data for modeling the individuals within the turma. It was used to determine how much spread there is in the turma formation. The movement of the formation as a whole, however, will be close to the average speeds and there will be only a little variation between units.



Next Page: Cavalry: Turmae Fighting Model


Site Map





© 2003, Gary Brueggeman. All rights reserved world wide. No part of this work may be reproduced in part or whole, in any form or by any means, without permission from the author.