War Horse

by Louis A. DiMarco

  The first and most numerous type of cavalry was the traditional Asian horse archer. Parthian tactics were similar to those employed by the Persians at Plataea, or even the charioteers of Egypt: the Parthian archers moved fast, refused decisive engagement, intimidated the enemy both physically and psychologically from a distance, and only engaged in close combat under favorable conditions.

  The Parthians also brought to the battlefield heavily armored cavalrymen, known to the Romans as cataphractii. In the Parthian military system the ratio of mounted archers to heavy cavalry was generally 10 to 1. The cataphractii evolved as a response to the steppe bowman. Each cataphract was armed with sword and lance, and he and his horse were heavily armored. The armor techniques used by the cataphractii emerged in central Asia (modern-day Uzbekistan) and were soon adopted by the Persians after the Greek–Persian wars demonstrated the shortcomings of lightly armored cavalry against hoplites. In theory a heavily armored cavalryman and horse could close with both light cavalry and heavy infantry and defeat them. The Persians never developed heavy cavalry in great numbers nor integrated them tactically with infantry and light cavalry. Thus, though they were present on the battlefield against Alexander, they were not exceptionally effective. However, once the concept of heavy cavalry was established, it evolved to become an important part of the Parthian war machine and later the centerpiece of the Sassanian armies.36

  Parthia and Rome exchanged invasions and raids for three hundred years. The Parthians achieved some notable successes, most dramatically in the victory at Carrhae in northern Syria in 53 BC. The Romans, however, were persistent in their eastern ambitions. The Romans sacked the Parthian capital, Ctesiphon, in 165 AD. This, combined with economic stress and political fragmentation, weakened the Parthian coalition sufficiently that the Sassanians could usurp its dominance.37

  The Sassanians established themselves as a power in the greater Middle East in 226 AD when the Sassanian king Ardashir defeated the Parthian ruler Artabanus V. Ardashir’s son, Shapur I, expanded the kingdom to include all of modern Iran and parts of Pakistan, Afghanistan, both sides of the Caspian, the Euphrates valley, and the Gulf Coast of the Arabian peninsula. Shapur’s expansion brought the kingdom into contact with Rome and established the Sassanians as Rome’s new eastern threat. Armenia was the prize both empires sought. The Sassasians inflicted a succession of defeats on the Romans, destroying Emperor Gordian III and his army in 244 AD, capturing Emperor Valerian and routing his army in 260, and repelling the invasion of Emperor Julian the Apostate and killing him as his army retreated in 363.38

  Much of the success of the Sassanian army was a function of elite heavy cavalrymen. These armored warriors, known as Savaran, wore long chain mail cloaks; their horses similarly wore armor to the hoof. Both Parthian and Sassanian cavalry wore iron helmets. The Sassanian cavalry favored a conical helmet, often with a nose guard. Riders typically wore a combination of armor: lamellar, laminated, scale, and mail. Mail was the preferred armor because of its all-round protection, flexibility, and comfort—it was made of open links and was much cooler. Mail could be worn over virtually the entire body. It was not, however, very effective against missile weapons such as arrows or javelins. Lamellar were small rectangular plates made of iron, bronze, or leather laced together vertically and horizontally. It covered large exposed areas such as the chest and back. Laminated armor consisted of metal strips, curved to match the body, overlapping and sewn to a leather sleeve. It was most useful for protecting exposed portions of the upper arms and legs. Scale armor consisted of small metal scales laced to a leather garment in an overlapping fashion. The scales were very small, allowing some flexibility in movement. Mail coats were the preferred armor of the Savaran, but often they wore additional armor over the mail. This was particularly true under Shapur II, when his super-heavy cavalry wore a long mail cloak under laminated and lamellar armor. When fully equipped the Sassanian super-heavy cavalryman could not mount his horse by himself.39

  The lance was the primary weapon of the Sassanian heavy cavalry. It was a long, heavy weapon that required two hands to wield effectively. Long straight swords with a broad guard were the secondary close-combat weapon of the heavy cavalry. The sword hung by a belt slide. All Sassanian cavalrymen carried a composite bow, which was an auxiliary weapon for the heavy cavalry. Sassanian cavalry carried a quiver of 30 arrows on the right hip and a bow case on the left hip. The heavy cavalry did not use shields, though some evidence suggests that shields may have appeared at the end of the period in the sixth and seventh centuries.40

  The Parthians used their mix of horse archers and heavy cavalry in an integrated manner that placed the role of the mounted archer first. The Parthians used heavy cavalry to keep the enemy infantry bunched up and disordered. This clustered group of infantry became the target of the bowmen. The Parthian bowmen also sought to draw out portions of the enemy line by feigning retreat. Pursuing enemy were led into a trap of massed mounted archers or surprised by heavy cavalry counterattacking. Numerous works of art depict the execution of this tactic. A Parthian bowman firing his bow to the rear as his horse gallops in the opposite direction gave rise to the phrase “Parthian shot.”

  Sassanian tactics initially were similar to Parthian—emphasizing the mounted archer, but over time the cataphractii came to be the most important cavalry type, and the two types of cavalry reversed roles. The heavy cavalry began the engagement by charging the enemy infantry with lances. This charge could either break the enemy’s line and be followed up by additional heavy cavalry or infantry, or, if unsuccessful, by a concentrated attack by horse archers, which in turn was followed by another heavy cavalry charge. As the Romans learned to form a tight infantry formation to repel the cataphractii, the Sassanians could break off the cavalry charge and surprise the Romans with a follow-up attack by heavy infantry. Bowmen were always in proximity of the cataphractii, providing harassing fire in support of the heavy cavalry.41

  Horses used by the Parthians and Sassanians are not likely to have varied much from those used by the Persians before them. Generally these would have fallen into three main types: a small Caspian type horse for archers and scouts, a medium-build Akhal-Teke type for general purpose cavalry, and a heavier Nisaean type horse for the heavy cavalry. Archeological evidence indicates that a coat of scale armor on a leather backing protected the Parthian heavy cavalry horses. Sassanian horses had their forward parts heavily armored, including chamfrons to protect the head and lamellar armor to protect the neck, shoulders, and chest. The Sassanians also used a saddle similar to the Roman horn saddle to provide stability to the cavalryman, particularly the Savaran, in close combat.42

  ROMAN CAVALRY TACTICS

  Roman cavalry performed a variety of tasks for the army. These included reconnaissance, security missions, and combat. All these missions were absolutely essential to battlefield success.

  Reconnaissance

  Vegetius warned that “the general, before he puts his troops in motion, should send out detachments of trusty and experienced soldiers well mounted, to reconnoiter the places through which he is to march, in front, in rear, and on the right and left, lest he should fall into ambuscades.” In the early Roman period there was not enough cavalry, and no cavalry independent of the legion, to carry out such a mission. This left the critical task of reconnoitering to the allies. During his campaign in Gaul, Julius Caesar relied heavily on Gallic and German cavalry. They located the enemy army and then probed for weaknesses. Caesar describes this role of cavalry: “daily . . . in cavalry actions, he strove to ascertain by frequent trials, what the enemy could effect by their prowess and what our men would dare.” These allied cavalry were individually superior to Roman cavalry, but because they lacked the formal training and structure of the Roman army they were often not reliable; reconnaissance, a noncombat task, was not part of their warrior culture.43 Once the foreign cavalry were formally incorporated into the Roman military system in the imperial period, the alae could be reli
ed on to perform this mission competently. However, on numerous occasions, Roman armies suffered reverses because the enemy surprised them. Often this was due to poor generalship rather than an inability of the cavalry to perform their missions.

  Security

  From the earliest republican armies, Roman commanders understood that security of the main body of the army was a critical function and one that was ideally suited to cavalry. The republic’s army organized a special force for this purpose called the extra-ordinarii. Made up of one-third of the army’s allied cavalry and one-fifth of the allied infantry, it performed special missions for the army commander, which allowed the core of the army—the infantry Roman legions—to remain intact. One of the most important of these missions was protecting the army on the march. Caesar indicates in his commentaries that they were also responsible for protecting the army’s foragers.44

  Roman armies required elaborate preparations prior to formal battle. Because it could take hours for the legions to properly deploy into formation, one important cavalry mission was to screen and protect this deployment. In the early republic period, when the cavalry was actually part of the legion, the legion’s own cavalry performed this mission under legion control. During the middle imperial period, the army commander used the cavalry alae to do the same.45

  Combat

  Roman cavalry engaged in combat as part of the main battle in the tradition of Alexander’s companion cavalry. Their role was to protect the flanks of the legions, destroy the enemy cavalry, and ideally, attack the enemy’s infantry flanks and rear. Vegetius emphasized that “the best and heaviest horse are to cover the flanks of the foot, and the light horse are posted to surround and disorder the enemy’s wings.”46 Javelin throws began the battle, followed by a charge to close with the enemy. Once in close combat, the cavalryman attacked with the lance, and used the spatha straight sword as the backup weapon. Fighting techniques among the alae varied. The early Gallic alae preferred the sword to the lance in accordance with tribal traditions. Late Roman heavy cavalry used the heavy contus lance as their primary weapon, while the eastern alae used the bow. As the enemy army was broken in the main battle, competent Roman commanders understood the devastating effect cavalry could have in pursuit and employed them in this role to the limit of their endurance.

  For most of the Roman period, the legion infantry were the center of the army in the minds of Roman commanders. Although Roman commanders seemed to grasp the critical importance of the cavalry, they were consistently unable to make a firm commitment to that arm. The Romans esteemed cavalry commanders but manned the force with foreigners, and for most of the history of the empire kept its size small. The military commentator Flavius Vegetius Renatus reflected the prejudice of Roman commanders toward foreigners in general and the cavalry alae in particular when he wrote, “Little can be expected from forces so dissimilar in every respect, since it is one of the most essential points in military undertakings that the whole army should be put in motion and governed by one and the same order. . . . And though the legions do not place their principle dependence on them, yet they look on them as a very considerable addition to their strength.”47

  ROMAN CAVALRY IN BATTLE

  Most of the important examples of Roman cavalry in battle are examples of their misuse or poor performance. Conversely, the cavalry opponents of the Romans, particularly the eastern enemies, were most often successful because of the superiority of their cavalry arms. Thus, though Roman cavalry of the imperial period and later were competent, they were often outclassed by the premier cavalry opponents of the period.

  Carrhae, 53 BC

  In the imperial period, gifted Roman commanders such as Julius Caesar understood and employed cavalry effectively, but they were the exceptions. The Roman army was generally successful in Europe fighting unorganized enemies such as the various Celtic and Germanic tribes, but as the empire moved east, it ran into civilizations that predated the Romans by hundreds of years which had effective military systems of their own. The terrain was open and the distances great. It was ideal for the employment of cavalry armies. Rome’s military record against the cavalry armies of Parthia and Sassania was undistinguished, and the border with these empires marked the limit of Rome’s ability to advance.48

  The limitations of the professional Roman army were demonstrated when it encountered the Parthians at Carrhae in 53 BC. Rome was in a transitional period between republic and empire. A triumvirate consisting of Marcus Licinius Crassius, Pompey, and Julius Caesar ruled unofficially. Political success in Rome required a combination of political acumen and wealth, which were related to military reputation and success. Caesar had achieved military victory in Spain and was in the midst of an even more successful campaign against the Gallic tribes. Pompey had recently conquered Syria and Palestine. Crassius, at age 60 and reputed to be the wealthiest man in the empire, needed a military victory to buttress his position within the triumvirate. He determined to achieve that notoriety on Rome’s eastern frontier against the Parthians.

  Rome had a neutrality treaty with the Parthians, but that was no obstacle to Crassius as he marched his army across the Euphrates River in 54 BC. A quick march and the capture of several Mesopotamian cities seemed to get the campaign off to a good start, but then things began to go awry. Crassius and his army were unfamiliar with the area. They originally relied on their ally, the Armenian king Artavasdes and his 6,000 cavalry, for support and advice. The king promised 10,000 more cavalry as well as 30,000 infantry. Advisors recommended that Crassius use Armenia as the invasion route. This would ensure a friendly base of operations, and the rough terrain would inhibit the Parthian cavalry. Crassius ignored this advice and invaded via the Euphrates river valley. Early in the campaign a Parthian invasion of Armenia caused the departure of the Armenian allies and a complete change in the tenor of the operation. With the departure of the Armenians, Crassius’s force consisted of seven legions—more than 30,000 infantry, 1,000 Gallic cavalry, 4,000 auxiliary infantry, and 3,000 auxiliary cavalry. The Gallic cavalry, detached from Caesar’s force in Gaul, were considered elite. However, they were not formally trained and equipped as an alae of the Roman army. As the Armenians departed, desert Arabs took their place as local expert advisers. Unfortunately for Crassius, the Arabs were more loyal to Parthia than to Rome.

  The Arab allies convinced Crassius, against the advice of Gaius Cassius Longinus, his senior lieutenant, that speed was critical and he should march his army on a more direct route through the desert, away from the security of the river. This route, which took the army into the open desert, exhausted the infantry, strained the army’s water supply, and was bereft of any natural protection against cavalry. Crassius hurried his force through the desert until his scouts returned to the main body reporting that they had made contact with a significant Parthian force prepared for battle.

  The appearance of the Parthians took the Romans completely by surprise. Cassius recommended deploying the army in battle line; instead, Crassius formed the army in a large hollow square. He divided most of his auxiliary cavalry evenly among the four sides to provide local protection. The square formation provided all-around protection from attack. However, it was an unwieldy formation for maneuvering or offensive action. The army advanced in this formation to a small stream. Here, the officers recommended stopping for the night to evaluate the situation. They still had not made contact with the Parthians and only had the vague reports of the scouts. The Romans did not send out any additional reconnaissance force. Crassius gave the order to move forward rapidly, before the army had completed watering at the stream.

  The Romans soon made contact with a body of Parthian horse archers but were not initially concerned because the Parthian force did not appear too large. However, as the Romans came under fire, the Parthians unveiled parts of their army previously hidden—including 1,000 cataphracts in full armor. The Parthians, for their part, had planned to begin the battle with a charge by the heavy cavalry, but the
y changed their plan when they observed the numbers and discipline of the Roman infantry. Instead, the Parthians opened the battle with a hail of arrows. The mounted archers soon surrounded the Roman square and poured a withering fire into the densely packed formation. Sorties by Roman light infantry to drive off the archers were unsuccessful.

  The Romans now realized that they were in contact with a substantial Parthian force but probably didn’t realize that they actually outnumbered the Parthians almost four to one. The Parthians, under the command of Surena, had about 10,000 archers and 1,000 cataphracts. But because of their mobility, this force was almost invulnerable to the Romans, who lacked sufficient cavalry to drive them off. The Roman shields and armor were of only limited protection against the continuous barrage of arrows. As the afternoon wore on, Roman casualties mounted. The Romans hoped that the Parthian supply of arrows would run low. When they realized that the Parthians had a camel train that continually resupplied the archers, the army became demoralized.

  At this point Crassius tried to change the dynamics of the battle and regain the initiative. He dispatched his son Publius with 1,300 cavalry—including all the Gallic cavalry, 500 dismounted archers, and seven cohorts of infantry (about 3,000 infantry)—to drive off the Parthians. The mounted archers quickly retreated in the face of this threat. Publius and his detachment, viewing the Parthians ride away, gave pursuit. After a short chase, the Roman detachment was out of sight of the main body. At this point, the Parthians ambushed the Romans with even more archers supported by the Parthian cataphract heavy cavalry. The Parthians killed most of the messengers dispatched to the army for support—but some got through. Slowly, Crassius reformed the army in a conventional battle formation and began to advance. But he was too late. The detachment under Publius, despite a spirited defense by the unarmored Gallic cavalry, was no match for the armored cataphract cavalry and was quickly overwhelmed. The Roman leaders in the detachment took their own lives. Before Crassius had advanced very far, Parthian horsemen paraded across the front of the Roman lines displaying the head of Publius on a spear. The Roman army halted and their morale plummeted further. While they remained stationary, archers fired a hail of arrows that inflicted more casualties. The cataphracts probed the Roman lines, pushing the Roman infantry into even denser formations and making them more vulnerable to the mounted archers.