Battle of Leuctra: A Military Masterpiece

On July 6, 371 BC, near Thebes in Boeotia, a major fight in ancient Greek history took place: the Battle of Leuctra. The Thebans, headed by Epaminondas the Boeotarch, defeated the Spartans, led by King Cleombrotus I, in a decisive battle. Many consider the use of the oblique order during the Battle of Leuctra, a crucial stage in the development of relations between Greek city-states, to be a tactical revolution. Once Sparta’s dominance was challenged, the city changed forever. Thebes rose to power and maintained it for ten years until Epaminondas died in the Battle of Mantinea in 362 BC.

The Background of the Battle

The political unpredictability that followed the Peloponnesian War ultimately led to the Battle of Leuctra. After their 404 BC victory over Athens, several parts of Greece were ruled by governments hostile to the Athenian democracy established by Sparta. The other great Greek towns were disturbed by this program because they were afraid Sparta would become dominant. Even though Sparta was facing social and political changes that left it without resources to maintain its programs, anti-Spartan sentiments swept across Greece.

Corinthian War

Known today as the Corinthian War, it began in 395 BC when Athens, Corinth, Thebes, and Argos banded together to confront Sparta. Thebes was a vital member of this alliance; hence, it was often the primary target of Spartan military assaults. Still in power in 371 BC, King Agesilaus II sent many expeditions into Boeotia beginning in 394 BC. The war between these two cities was far from over when the Corinthian War ended in 386 BC. Although Sparta failed to completely destroy Thebes militarily, it did succeed in convincing Thebes to give up its attempts to conquer Boeotia, a territory in central Greece.

In 382, during an expedition against the city of Olynthus, Sparta seemed to triumph over Thebes and topple its government by seizing possession of Thebes. There was a widespread exile of Theban leaders during this period. Other important Greek towns, as well as certain Spartans like King Cleombrotus, condemned the Spartan conquest of Thebes. The Spartans’ rule over Thebes didn’t last very long. With assistance from Athens, the exiled Thebans retook the city in 379 BC and slaughtered the remaining Spartan troops. Cleombrotus I, the king of Sparta, who had first resisted the occupation, could no longer take this and led multiple expeditions against Thebes.

The first conflict occurred in the year 379 BC. The king of Sparta was wary of attacking Theban land or crossing the Cynoscephalae, a range of mountains in Boeotia between the cities of Pharsalus and Larissa. Cleombrotus’ hesitance to attack Thebes allowed the city to strengthen its defenses and so grow to prominence. The threat of Theban expansion over Boeotia prompted Sparta to organize a second expedition in 376 BC. Cleombrotus resumed leadership. Nonetheless, this effort was cut short too soon. Xenophon claims that the Thebans successfully repulsed the Spartans from Mount Cithaeron in Boeotia.

The tension between the two cities did not abate. When Thebes reinstated the Boeotian League in 373 BC, a new era began. Athens contacted Sparta in an effort to mediate peace due to the rise of the Thebans. The invitation to these talks was accepted by Thebes only after the city insisted on being recognized as the dominant power in Boeotia.

These demands were too much for Sparta, so Cleombrotus I led a new campaign against Thebes. The Spartan army included around 7,500 allies, 1,000 cavalry, and 1,600 Neodamodes (former slaves without full citizenship rights) in addition to 700 Equals (Spartan elite). The armies of Sparta and Thebes moved forward toward each other in preparation for a last showdown.

How Did Sparta Get Ready to Battle?

After receiving instructions to advance, Cleombrotus led his troops far into Boeotia. His defending soldiers, who had been stationed in Phocis, stopped at the Theban town of Leuctra, which was inside Thespiae’s borders. After inheriting two decades of hostility, the armies’ respective leaders fought for different reasons.

The Spartans’ pride was on the line if they took on and lost to the Thebans. The commanders of Sparta recognized the importance of this and made extensive efforts to convince Cleombrotus to fight despite his initial hesitation.

The reputation of Sparta as a military power had been severely damaged by their failed operations against Thebes in the past. Cleombrotus’ past excursions, which were marked by hesitancy and caused substantial damage to the Spartan force, were in stark contrast to Agesilaus II’s triumphs.

The leaders of Sparta did not hesitate to use threats of banishment to exert pressure on their monarch. They advised him to fight for himself if he wanted to return to his country. These threats were fanned in part by those who argued that Cleombrotus, king of the Spartans, had been too kind toward the Thebans. The Spartan ruler would be more galvanized into a fighting spirit by such comments.

Therefore, Cleombrotus felt obligated to accept the proposal. This worked against the Spartans because it seemed that their authority was fractured; their king, in particular, was reluctant to battle. As Xenophon points out, the state of the Spartan commanders, who drank heavily before the war and were “somewhat excited,” could only have reduced their efficacy.

The Spartans, on the other hand, had a number of advantages that made them more likely to choose war. The Thebans fielded less than 6,000 troops, whereas Sparta’s army numbered around 11,000, thanks in large part to the contributions of Phocis, Heraclea, and Phlius. In addition, the Spartans’ commitment was strengthened by the fact that they could lose their backing if they lost the battle.

However, Xenophon pointed out that “among the allies, no one had the heart to fight,” suggesting that the allies were not very enthusiastic about fighting. Cleombrotus had to welcome the approaching conflict if he wanted to keep his political influence on Sparta.

How Did Thebes Get Ready to Battle?

In spite of their numerical disadvantage, the Thebans are drawn into conflict by political concerns. The first step for Thebes must be to strengthen its position in the area. Xenophon claimed that the Theban government was worried that if they pulled back, the surrounding cities would side with Sparta. This result had the potential to be very bad for Thebes. Considering how recently and violently Theban power was established in the area, these towns could offer Sparta new soldiers.

However, if citizens of Thebes were to desert, it would severely damage the city’s political standing and its claims to rule over all of Boeotia. Moreover, Theban leaders worry about their own self-interest. Because of their painful experience during the Spartan captivity of Thebes, the Thebans were understandably reluctant to embrace the possibility that their fellow citizens could judge and banish them if they were to withdraw without fighting.

But the Thebans were not only motivated by politics; they also had a number of things on their side that provided them with moral and military superiority. A Spartan exile named Leandrias reportedly helped them out. This is according to Diodorus Siculus. The Thebans could greatly benefit from having a man who presumably had close encounters with Spartan hoplites so that they might obtain a more nuanced grasp of Spartan tactics.

According to Diodorus, the fact that a Spartan exile existed at all is evidence of an ancient prophecy that foretold Theban’s triumph. Leuctra’s presence in this setting gave the Thebans a significant boost in morale.

According to Xenophon and Diodorus, a local oracle or group of prophets predicted an unassailable victory for the Thebans. Both writers provide extensive accounts of the tale upon which these claims are founded. Spartans allegedly raped girls in Leuctra, after which the victims cursed them and killed themselves. It was thought that the Spartans could only be vanquished in such an infamous location. The moral high ground in this story was bolstered by other reports of miraculous happenings that supposedly proved the gods were backing the Thebans.

Xenophon questions the veracity of the stories, but he nevertheless recognizes their outsized impact on the culture. As a result, the Thebans found themselves in a rare situation that, when paired with tactical improvements, finally led to triumph while being driven by political limitations yet equipped with a considerable moral edge.

The War Unfolded

The Spartans charged into the fray, testing the might of the Theban line. They achieved this by sending their peltasts, armed with javelins, to attack the Theban light infantry. Although cavalry conflicts were uncommon in hoplite wars, the Theban and Spartan cavalry unexpectedly joined the combat by positioning themselves in front of their respective phalanxes. In this surprise encounter between the two cavalry forces, the Thebans emerged victorious, leaving the Spartan cavalry in confusion.

This first battle ended up being crucial to what happened thereafter. The Spartan cavalry, having been soundly routed, fled across their own phalanx lines, creating confusion and further weakening the already unstable cohesiveness of the ranks, which had already been weakened by the presence of inebriated hoplites. The Theban cavalry, meanwhile, moved to a new position in front of the phalanx. This tactical adjustment helped to hide the Theban formation’s reinforced left flank from the Spartans.

The Birth of the Oblique Order

While most generals would put their strongest soldiers on the right wing, Epaminondas instead faced the Equals, an elite Spartan phalanx, with his best men on the left. Many people, including Diodorus Siculus, apparently thought that “the wing where elite troops were stationed would determine the battle’s outcome.” Putting one’s finest soldiers on one’s left flank was an unorthodox strategy that caused major disruption to established tactics.

Scholars have speculated on Epaminondas’ possible reasons for making this choice. Despite knowing he was outnumbered, the Theban strategist seems to have planned a daring move to challenge the Spartan elite. Once the Thebans “defeated the wing that was with the king,” Xenophon claims, “they would easily be masters of everything else.” The Spartan right wing was the most dangerous element of their phalanx, and if it were defeated, the remainder of the Spartan soldiers would likely split and run.

While these are the most common explanations for the change in strategy, other writers provide different perspectives. They hypothesize that Epaminondas tried to protect his less committed comrades from fighting, fearing that they would become resentful if they were pitted against the elite Spartans. Some writers even go so far as to attribute the philosophical inspiration for the leftward shift to Pythagorean ideas on cosmological symmetry. At any rate, breaking with custom by putting the Theban elite soldiers on the left was a huge move.

Epaminondas also made another significant adjustment that ended up being crucial. To make his onslaught more effective, he decided to significantly strengthen his left flank by deploying his elite men there. For example, Xenophon emphasizes how “the Thebans, on the contrary, had a close formation of at least fifty shields in depth.” Epaminondas’ response was to form a massive phalanx on his left flank. About 2,000 warriors formed this phalanx, which was unusually large for such a configuration (50 ranks). The Spartan configuration at Leuctra, like most others, included hoplite phalanxes no deeper than 12 shields.

However, Thebes tried something similar in the past. At the Battle of Delium, they lined up 25 phalanx units to take on the Athenian army. Xenophon notes, however, that the majority of this large 50-rank phalanx was bolstered after the previous harassment of non-combatant Thebans by the allies of Sparta. This tight formation gave the Theban warriors more momentum and striking force to make up for their inferior training and burst through the Spartan lines. It was also crucial that Epaminondas make the call to reduce the width of the front of the phalanx. The plan was to strike at the very heart of the Spartan Equals. A smaller front of 40 troops was now protected by 2,000 Thebans, while the larger front of 60 men was provided by 700 Spartans. The Thebans greatly improved their prospects of making progress toward their goal by increasing the intensity of their pressure in the middle.

Epaminondas modified the traditional hoplite strategy by reducing the strength of the right flank and bolstering the left’s enormous phalanx. As a result, the Theban phalanx had a particularly weak spot where the Spartans could easily break through: its right flank. According to Diodorus Siculus, Epaminondas addressed this by ordering his right wing to avoid battle and even perform a “gradual backward movement” as the Spartans closed in.

Epaminondas thus coordinated a powerful left wing charged with making a breakthrough and a vulnerable right flank tasked with holding the Spartans at bay. Diodorus called this formation of soldiers fighting in an oblique formation an “oblique phalanx.” The oblique order was established.

Were the Phalanxes Successful?

After their cavalry had such a spectacular victory, the Theban phalanx moved forward to attack the Spartan right flank. In this fierce conflict, the superior skills of the Spartan hoplites really shone through. However, the Equals ran into trouble because of their lack of unity which could be traced back to King Cleombrotus’ eagerness to meet the enemy.

According to Xenophon, Cleombrotus assumed authority before “his troops realized that he had taken command.” In spite of all of this trouble, the Spartans held out against the Thebans for a long time. Spartan heroism was praised by both Xenophon and Diodorus, who, according to Xenophon, “fought with such ardor that the battle remained undecided at first.“

This is important because the Thebans’ success wasn’t guaranteed the moment the oblique order was implemented. According to Xenophon, the death of Cleombrotus was a turning point that ultimately contributed to the fall of the Spartan forces. His death was quickly followed by the deaths of other Spartan leaders, including the polemarch Deinon. For the Spartan wing, the near-simultaneous deaths of their leaders were an emotionally devastating blow. These men had fought side by side with their warriors for a long time. Therefore, “the bodies piled up around [the king],” as Diodorus puts it, suggests that this wing either dissolved or chose to face its destiny on the battlefield.

Both versions agree that the Spartans briefly held off the Thebans and brought back their dead king’s corpse before dispersing and running away. After Cleombrotus was killed, the Spartan right wing collapsed, thus ending the conflict. Xenophon captures a crucial point when he writes, “The left wing of the Lacedaemonians yielded upon seeing the right wing retreat.” Overcoming Spartan tradition and the conventional understanding of hoplite combat, the oblique order emerged victorious.

The End of the War in Numbers

At first glance, the battle’s tactical result may be seen as unremarkable, with relatively low numbers of Spartans killed or captured. Most accounts, following Xenophon’s lead, agree that 1,000 Spartans and 300 Thebans were killed. These are not incredibly high numbers, but they are consistent with the standard percentages for casualties in hoplite fights, which normally include 15 losses for every 100 men for the losing side and 5 losses for every 100 men for the winning side. Even though they suffered heavy losses, the Spartan army was able to return to their camp in relatively good shape, where the Thebans were understandably apprehensive to attack.

Xenophon shows the Spartans’ ongoing fighting capability by mentioning that some Spartans favored restarting hostilities straight away, despite the hesitance of their friends and the large deaths among the Equals.

A closer look at the casualties casts doubt on the idea that the Battle of Leuctra was a typical war. Xenophon stresses an important fact: out of the thousand Spartans killed in combat, 400 belonged to the seven hundred Equals present. For Sparta, these deaths amounted to nothing less than a demographic disaster. Its political and military leadership were wiped out in a single day, and almost a third of the population died as a result.

The right wing of the Spartans lost more than half their troops when challenged by the powerful Theban phalanx which was an impressive resolve. This was in sharp contrast to the standard loss of “15 losses for every 100 men” that was assigned to the losing army. This war and the oblique order came to symbolize the evolution of Greek warfare, which shifted from skirmishes between surrounding agrarian communities to battles between regional powers vying for dominance.

Historians have praised Epaminondas’ military placement as a “tactical revolution” since antiquity. Historians have made an effort to put this perspective in its proper historical context by highlighting the fact that this strategy, which has long been credited entirely to Epaminondas’ creativity, was really in use by the late 5th century. Perhaps strategic development led to the outcome of the Battle of Leuctra.

Epaminondas Was Downplayed

Since Xenophon is the only historical source for the Battle of Leuctra, the prominence of the most famous of the Theban generals, Epaminondas, might be downplayed by focusing on the fact that his name is conspicuously absent from the text. Epaminondas’ fame has been passed down through the ages thanks to the writings of ancient historians like Ephorus of Cyme and Diodorus Siculus.

What Made the Battle of Leuctra Crucial?

Even if the Spartans were defeated at the Battle of Leuctra, it did not mean Thebes would win the war against its archrival. Despite the heavy casualties among the Equals, several Spartans contemplated mounting a second assault on the Theban army before their allies stopped them. The two armies resolved to continue their customary ceasefire, and the Spartans retreated to their base. Thebes had won and gained moral superiority, but they were unable to capitalize on the situation at this time.

The tyrant Jason of Pherae, who dominated the Thessalian city of Pherae, really sided with the Thebans not long after the war. After plundering Phocis on his way to Leuctra, he now appeared with troops. The Thebans wanted to launch an attack on the Spartan camp with this bolstered force. But the tyrant’s true motives were less noble, and he could try to dampen the joy of his friends after their triumph at Leuctra. Although he failed to broker a ceasefire, his efforts showed that Thebes’ triumph was not very decisive. When the Spartans began their withdrawal toward the Peloponnese, they couldn’t follow them since they still needed to handle their allies.

As if the Boeotians’ internal problems weren’t bad enough, Sparta’s quick reaction to Cleombrotus’ withdrawing army only made things worse. As soon as word of Sparta’s loss at Leuctra spread, the city’s eligible male population under the age of 60 was mobilized into a second army.

When he incorrectly refers to “another army” that Cleombrotus purportedly met before the Battle of Leuctra, Diodorus was actually referring to this force. Diodorus falsely presents Archidamus, the son of King Agesilaus, as taking part at Leuctra, when in fact the second army was only organized in reaction to the Spartan loss and put under his command. The campaign of 371 BC was over when the reinforcement army caught up with Cleombrotus’ main force during their full-scale retreat and headed back to the Peloponnese. The rapid deployment of a second Spartan army demonstrated that the city-state was not conquered and still had access to formidable military forces.

Although Thebes’ victory at Leuctra was tactically a turning point, it did not instantly translate into a strategic triumph. For Thebes to finally dominate Sparta, it would need a new military expedition in the year 370 BC. But the conflict between the two city-states continued until 362 BC, when Thebes finally won with a decisive victory at Mantinea. General Epaminondas was lost, and Thebes was unable to establish its hegemony in Greece and stayed bitterly divided until it ultimately fell under Macedonian dominion.

Historical Data from Ancient Sources

Ancient sources describe the Battle of Leuctra, but their accuracy and reliability may be questioned due to the different time periods in which they were written, as well as the absence of direct sources from participants in the battle. The main ancient sources regarding the Battle of Leuctra include:

• Xenophon: Hellenica, Book 6, Chapter 4: Xenophon was a contemporary of the events and a professional military strategist. His work is considered to be the closest to primary sources.
• Diodorus: Library of History, Book 15 (45–56): Diodorus was a Roman historian who wrote about 300 years after the battle. His works may contain significant contradictions.
• Plutarch: Pelopidas, Parallel Lives: Plutarch, who lived about 450 years after the battle, included descriptions of the battle in his work. His writings do not have clear references to primary sources, and their accuracy is subject to doubt.
• Pausanias: Description of Greece, Book IX Boeotia, XIII: Pausanias was a literary figure and traveler, and his account of the Battle of Leuctra presents the Theban version of events. His works are rarely used for this battle.

Xenophon, despite his connections with Sparta, is considered to provide a balanced analytical view of the events rather than mere Spartan propaganda.