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Considering the Battle at Leuctra

Jack R. Parnell

Spring, 2022


The most feared army in all of Greece was broken in Boeotia, on the field between Thespiae and Plataea, in 371 BC. There, Cleombrotus I became first Spartan king to fall in combat since Leonidas perished at Thermopylae. With him faded the Laconian hegemony that ruled the region from the end of the Peloponnesian War. The battle at Leuctra was unavoidable, and historians argued over Leuctra even while it was still in living memory. Modern historians continue to disagree as to specifically how the battle was won by the Thebans, or as to the precise moment, or reason for why the Spartans lost.

The narrative by which we organize history is a difficult mixture of fact, and of social, political, or moral apocrypha. Those moments in the past that seem to us to be most decisive, tend to be difficult to apprehend upon close inspection; either due to the innate complexity of historical crossroads, or because of their resultant over-handling by historians. Pivotal events become yardsticks of the zeitgeist. 

The virtues supported by one particular telling come in-and-out of fashion, and Leuctra is not well served by the tendency of institutional historians to treat it as a neatly-drawn fable: A tyrannical rule came to a sudden end. A peerless army was defeated. The tenacious but less-formidable soldiery found an opening through cunning, and seized it with act of bravery. The situation is made worse still because the famed and traditional discipline of the Spartans, together with the eccentric tactical strategies of the Thebans, came to represent a modern tendency—to conceive of important moments in history according to a ‘progressive’ frame of mind, and then to celebrate the Thebans for it, as if it justifies us. 

The political condition at the end of the Peloponnesian War is better described as a state of exhaustion, than a decisive conclusion—as evidenced by the Corinthian War. Following the failure of more direct means of control at Marathon, Persia engaged in a host of political games, in an attempt to blunt the Greek powers against one another. Such political machinations generally ensured that no true supremacy could feasibly take shape in Greece among the warring city-states. When the Peloponnesian War finally drew to a grueling conclusion the Persians then shifted their support away from Sparta, and over to the remaining city-states. Athens overthrew its installed government, and then returned to war—facilitated not only by the Persians, but also by the Spartans’ own ungenerous treatment of their allies during the Peloponnesian War. The scorned cities, specifically Thebes, found enough success fighting alongside the Athenians against the Spartans, that the Persians felt it worth their while to lend their support to the Laconians once more. It was a switch that led Athens to seek an end to the war. Thebes, however, was again left somewhat unfulfilled in its appeasements by the treaty. The Theban desire to consolidate its power over central Greece, and of Sparta to do the same, lead both to seek a political excuse to resolve the question of who would rule, for themselves. As history would have it however, the Theban-Spartan conflict resulted in a new hierarchy of power dominated by neither; but by Macedonia in the north.

The heart of ancient Greek soldiery was the hoplite; a heavy infantryman levied from citizenry who were wealthy enough to equip themselves. He comprised the central fighting force of every city-state. The hoplite’s primary arms were the broad circular shield, a spear roughly ten-foot in length, and his sidearms. Traditionally, Greek military tactics were dedicated with almost exclusive focus on the disposition of the hoplites on the field, who were seen as the decisive element of battle. Other troops—skirmishers and cavalry—were treated moreso as a tangential detail; an attitude exemplified in Spartan war-making, as they were unequalled in the prosecution of those tactics and fielded the finest hoplites in the peninsula. Such a philosophy however, meant that skirmishers were frequently relegated to mercenary troops and that the Spartans only adopted their own cavalry corps late in the Peloponnesian War. 

In sharp contrast with their heavy infantry, Spartan cavalry was ill-trained and poorly equipped. There was a certain lack of prestige for a cavalryman in Laconia, and because of the demanding resource-requirements for maintaining horses, often the circumstance was that men of low station were issued horses belonged to infantrymen during the campaign, to serve as cavalry themselves. The result was a cavalry largely composed of men with next-to-no skills in horsemanship; men who were neither acquainted with fighting from horseback, nor in formation. Thus far, the questionable quality of the Spartan cavalry was vindicated by the potency of the Spartan phalanx—a tight formation of hoplites which allowed more disciplined soldiers to support one-another through drilled formation, which minimized the reliance of the army on individual skill and numerical advantage. A well-maintained phalanx could easily resist assault by any contemporary cavalry, provided it was attacked from the front. The primary weakness of a phalanx was its slow, and ungainly capacity for turning itself—a point which proved crucial at the battle of Leuctra. 

Because the Spartan phalanx was only properly vulnerable to attack from the flanks, the Spartan cavalry only ever needed to be fit enough to secure the hoplites’ flanks for long enough, that the hoplites could win the battle. It is precisely because of the Spartan’s tactical success that the leaders of the Boeotian league were pressured to find some nuance in their own engagement strategy, rather than to try and beat the Laconians at their own game.

The Theban scheme at Leuctra should perhaps more accurately be described as the tactics of Epaminondas himself, a Beaotarch of the Boeotian League and general of the Theban armies. He is regarded, now, as one of the preeminent military minds of his time—though many of the details of his life have been lost to history. A reserved and reclusive man by nature, Epaminondas is thought to have been drawn into the political sphere because of his close friendship with Pelopidas, who was a prominent Theban politician. While Epaminondas was responsible for the disposition of all of Thebes’ might, it was his friend, Pelopidas, who led the most elite contingent of Theban hoplites: The Sacred Band. 

Greece had been in a state of war for verging on a century by this point, and Thebes fielded an established core of hardened veterans not only within their infantry, but also their cavalry. Theban horsemen were used to working in concert with heavy infantry, but they also fought with a unique group of light infantry skirmishers who were mobile enough to act in unison with the horsemen. In a perhaps inelegant summation, it could be said that the Thebans were strong where Sparta was weak, and where the Spartans were peerless, the Thebans remained formidable. 

Thus far, mention of the allied states and of the mercenaries fighting alongside both belligerents has been avoided, not only because they were secondary actors, but because the details of the battle bear out a lack of wherewithal among them. Through attrition, the rest of Greece was content to let Sparta and Thebes determine between themselves who would reign. The formations deployed at Leuctra allowed this exchange to take place, in such a way that the Thebans and Spartans only bloodied themselves.

King Cleombrotus I of Sparta positioned his campaigning force to strike at Thebes well before Epaminondas even refused to sign the treaty—written to prevent the outbreak of war. Both seemingly decided, then, that force was the only way to answer the question of power between them. No sooner did the Boeotian League leave negotiations than did Cleombrotus’ readied force circumvent a fortified defile on the border of Boeotia—having marched through a mountain pass—and seized several naval vessels. The Spartan king was suddenly within direct striking range of Thebes, when he was confronted by Epaminondas on a flat plain outside the village of Leuctra. 

The Theban general did not want a siege. He believed a pitched battle was their best chance at victory. Also of consideration for Epaminondas was the reluctance of other Boeotians to fight. Epaminondas had to either use his army now, or lose it. Similarly, across the field King Cleombrotus was operating under the weight of political antagonism from home, in Laconia. His respect for Thebes as an opponent was well-known, and provided his political enemies with an avenue to create the narrative that he was soft on the Boeotian league. Even his closest advisors believed that if he did not face Epaminondas in battle, he would face exile upon his return. 

Though the precise figures are disputed, both forces were evenly matched at roughly 10,000 men. And while it’s generally agreed that the Spartans and their allies outnumbered the Thebans, we must also consider that Theban cavalry specifically outnumbered the Spartan cavalry. Additionally, of the Spartan-led force only some 2,000 originated from Laconia, and of those, only 700 were Spartan citizens. With odds this close, either commander might have preferred to avoid a pitched battle in favor of pursuing a diplomatic resolution more heavily in their favor. However, political pressures on both sides required a more visceral conclusion to the conflict. 

For the Spartans, the formation was a matter of consistent, tactical precision. Hoplites would be arrayed in phalanxes roughly eight men deep, with the most disciplined and experienced troops down the right side of the line. Such a traditional formation worked to avoid the tendency of less-disciplined phalanxes to wain right, exposing the flank to the enemy. By stationing the Royal Guard and his most experienced hoplites on the right, Cleombrotus could keep the entire band in reliable formation. The Spartans’ plan was to outmatch and defeat the opposing Boeotian hoplites, and to expose the Theban flank—the assumption being that the Theban formation would mirror the Spartan formation. For the Thebans not to do so, would jeopardize their phalanx for the same reason, and risk a total route by the superior Spartan infantry. Cleombrotus’ skirmishers and cavalry were to be positioned to secure the heavy infantry from disruption by enemy cavalry and skirmishers. These strategic configurations enjoyed traditional status because deviation from them led so frequently to defeat. 

Epaminondas, however, deployed several variations from traditional formation in an attempt to manage the threat posed by the prowess of the Spartan Royal Guard. First, he reinforced the Sacred Band with troops from the other Boeotians. Whereas the phalanxes deployed by the Spartans were about eight men deep, Pelopidas led a phalanx fifty men deep. What’s more, he led it from the Theban left, directly into king Cleombrotus and the Spartan Royal Guard. Next, in order to keep the skirmishing elements of his army from having to engage; in order to draw out the inevitable disarray among those flightier soldiers—which was sure to result from his eccentric tactics—Epaminondas staggered them backward, at an angle, away from the Spartan line, so as to still cover the right flank of the Sacred Band. The other Spartan troops, therefore, could neither support the Royal Guard without exposing their flank to the staggered Theban line, nor could they easily engage the inferior soldiery because of the distance. The Theban formation was thus able to narrow the crux of the battle from the full line of two engaging armies, down to just the two engaged phalanxes: The reinforced Sacred Band, and the Spartan Royal Guard. In essence, this maneuver took back the numerical advantage for the Thebans by an impressive margin. 

It is important to note that Epaminondas’ formations are not entirely without precedent in the history of Greek military engagement—even recent to the battle at Leuctra—but were not in concert, and such tactics were often the result of necessity moreso than cunning. Epaminondas’ eccentric deployment at Leuctra is the primary reason for his general acclaim. The story is tidy: A force which could not be defeated, laid low because of daring new tactics; it clearly demonstrates the virtue of progress, and of innovative thinking—triumphant over rigid traditionalism and ignominy. It is a neat enough parable, but moreover, one which does away with enough of the reality of the battlefield, as to be useful only if one has motives beyond the historical. This is because of the last, and most important, feature of the Theban deployment at Leuctra—the cavalry. 

The problem with deploying a phalanx much deeper than twelve men, is that the weakness of its vulnerable flank becomes less and less manageable as the phalanx deepens. The longer the flank is, the more exposed it is, and the more difficult it is for the phalanx to maneuver reliably and defend itself. Each line added to the phalanx, while adding momentum and support toward the front, is an exponential liability. One of the simplest reasons that a phalanx was rarely deployed anywhere nearly as deeply as the Theban formation, was the expectation that it would be flanked and summarily routed. The longer the flank, the more area there is to engage the formation on the edges, where it is weakest. Such a deep phalanx desperately invited the enemy to outmaneuver it—and, its depth and ungainly configuration would disallow the unit to turn and face the flanking attack in tandem. Future adaptations of this tactic involved much deeper consideration and variation given to the security of armies’ flanks. The Spartans would have been intimately aware of this fact, even upon seeing Epaminondas’ deployment on the field. Cleombrotus moved immediately to use the odd Theban formation against them to devastating effect, and would have, had the Royal Guard’s flanking maneuver not been interrupted by the Spartans’ own cavalry.

Epaminondas placed his cavalry directly in front of his lines, rather than locating them more traditionally along the flanks. While this positioning might seem counter-intuitive; exposing the flank of the already precariously deep phalanx, it provided them an advantage specific to the Theban deployment at Leuctra. Should the Spartans attempt to reform in order to find the flank of Epaminondas’ deep phalanx, the Theban cavalry would be right there to intervene with the infantry. Thus, Cleombrotus was forced to deploy his own cavalry in front of his lines as well, to screen against that Theban tactic. 

With this single move, the Spartan cavalry suddenly went from a tangential detail of the battle to a crucial component—a role for which they were completely unprepared, especially against the Thebans; the finest cavalry in Greece. 

The Thebans utterly crushed the Spartan cavalry. Their victory in the skirmish was so decisive that they not only routed the Spartans, but encircled them. They drove the Spartan cavalry back over their own lines, and shattered Cleombrotus’ infantry formation as it attempted to maneuver into a position to punish Epaminondas, and his eccentric phalanx. The Spartan hoplites were left to fight in individual disarray when Pelopidas and the Scared Band collided with the heart of the Spartan line. 

The fighting was brutal, and the charge stalled until king Cleombrotus was mortally wounded. Despite the fact that the Spartans couldn’t have been in worse position to receive the charge of the deepened phalanx, they still controlled the field well enough to allow Cleombrotus to withdraw to their camp, but at devastating cost. Nearly 400 of the 700 Spartan citizens—an already dearly winnowed population from the continuous wars—were slain. When Spartan allied forces saw that Cleombrotus had fallen, they abandoned the field. The battle was ended in a resounding victory for Thebes. Cleombrotus died on the field of his wounds.

While the victory allowed Thebes to invade the Spartan homeland, and to free many of their slaves in a manner ruinous to their economy, it did not lead to a decisive conclusion to the war. Epaminondas died soon after by a Spartan sword at the tip of his new formation, while laying siege to the Laconians, in their fourth attempt to invade the Peloponnesus. Thebes established dominance over Greece, but lost much of its martial nuance with the death of its preeminent general. The enduring victory was for foreign powers. Persia was free to manage its affairs without Greek meddling, or fear a united Hellenic army. Macedon, under Philip, was then eventually able to lay claim to each of the exhausted city states, save Sparta. Sparta only gave way at last to Philip’s son, some years on. 

It’s a decidedly less compelling story—the idea that when the legendary warriors of Sparta were finally defeated; when the Spartan hegemony was ended on the battlefield, it was a consequence of decisions made decades before rather than the result of one daring general’s unorthodox mentality. The lens of history has long been focused on the peculiarities of Epaminondas’ deployment. Historians speculate about the reasons for Cleombrotus’ formation, with little-to-no notice paid to the fact that the battle was arguably lost before the Spartans took the field. The Spartans were plagued by exhausted allies without the will to fight, by scant numbers after decades of war—for a state that depends on its citizen soldiers—and by an outright disdain for cavalrymen. Sparta didn’t have the numbers, in the ways that mattered, to exploit the Theban gambit. Cleombrotus may have known this, if not at the start of the day then certainly by the end of it. His death at Leuctra could perhaps be called deliberate in a meaningful capacity—an honorable man who took the only estimable path left to him, at the conclusion of a century-long conflict. 

Epaminondas for his part was a fine commander despite it being presently fashionable for historians to lionize his tactical gamble—but the idea that Epaminondas’ unorthodox formation was the single stroke of genius which unraveled the Spartan war machine remains unconvincing. Compared to the weight of decades of attrition, flawed doctrinal decisions, and the destructive flight of panicked Spartan cavalry, Epaminondas’ strategy was well-facilitated by the Spartans themselves. While no man is equal to his own legend, perhaps Epaminondas ought only to have the laurels for the battles he won, instead of being crowned victor in the ideological skirmishes between modern institutional academics.


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