1. Background

In the aftermath of the Peloponnesian War of the late 5th century B.C., interstate alliances became tools used by various states to bolster their own positions. At the beginning of the 4th century, the Corinthian War (395-387 B.C.) marked a high point in such interstate relationship reversals, with Sparta opposed to the unlikely alliance between Thebes, Athens, Corinth, and Argos. At the war’s close, the King's Peace treaty (also known as the Peace of Antalkidas) of 387/6 B.C. essentially left Sparta in control of protecting the peace between states. One of the treaty’s stipulations was to dissolve existing alliances and leagues between city-states. Thus, on the pretext of protecting the freedom of Greeks, from the Peace until 371 B.C. Sparta began to focus on breaking up alliances that posed a military threat to Sparta. Such breakups included the dissolution of the Boeotian Confederacy, a league at whose head had sat Thebes.

2. The Rise of Thebes

In 382 B.C., Sparta moved north with the hopes of dissolving the Chalkidean league. Along the way, the Spartans took Thebes and installed a military garrison and oligarchic government on the Kadmeia, driving the opposition into exile. At the same time Sparta also established ruling Spartan officials in other strategic city-states in Boeotia. Such deliberate and hostile actions were unspecified in the King’s Peace and thus violated it.

In 379 B.C. Theban exiles, now living in Athens, planned a revolution against Spartan occupation. Two of these revolutionaries were Pelopidas and Epaminondas, undoubtedly the two most significant Theban leaders of the fourth century. Pelopidas arrived in Thebes with his mustered forces and gained entry to the city. Epaminondas met him with more revolutionaries. After much violence in which many of the Spartan leaders and pro-Spartan Thebans were killed, Sparta surrendered Thebes back to the Thebans. Sources report that in 378 B.C. Pelopidas helped establish a democracy in Thebes, possibly a radical one, and as elected Boeotarch, Pelopidas helped reinstitute the Boeotian federation under Thebes with a remodeled constitution. One of the contributions of Thebes to the history of political formations was this new style of democratic federalism involving direct federal citizenship.

The following year (378), Athens allied with Thebes, claiming that Sparta had breached the Peace of Antalkidas by attacking the port of Piraeus. Over the next few years Athens was to prove instrumental in helping Thebes weaken Sparta by attacking Sparta’s navy while Thebes concentrated on removing the remaining Spartans from across Boeotia.

After 375 BC Pelopidas took on the command (lochagos) of the newly formed Sacred Band, an elite Theban corps of warriors, the organization of which the sources attribute to Gorgidas (Plutarch, Pelopidas 18-19). Pelopidas is reported to have led the Band from that time until his death in 364.

The Thebans and their Boeotian allies concentrated on removing various groups of Spartans from Boeotia and in 375 B.C. inflicted an important defeat against Sparta at the battle of Tegyra (near Orchomenos). Although a relatively small skirmish, Tegyra resulted in Theban victory on the basis of Pelopidas’ strategy of grouping the new Sacred Band as a unit together facing two contingents of Spartan warriors and protected by coordinating Theban cavalry. Tegyra marks the first historical point at which a largely-outnumbered force defeated a more numerous Spartan army. As often with fourth-century Boeotian events, Plutarch is the main source for this battle (Pelopidas 16ff). He considered Tegyra a prelude to the more famous battle of Leuktra, but as Beck notes (2008), these battles do not share many significant details. They rather resemble each other only in Pelopidas’ victory over more numerous Spartan forces.

With Persian encouragement, from 375-372 B.C. Sparta, Athens, and other Greek states tried reinstating the King’s Peace. For Thebes, a revised Peace meant a second breakup of the Boeotian federation and no further consolidation of power within Boeotia, such as the hostile takeover of Plataiai, a Boeotian community that had long-lived traditions of non-compliance in Boeotian federal affairs. Thebes in fact destroyed Plataiae in 372 B.C. and also removed the fortification walls of Thespiae, a city-state in western Boeotia. At a peace conference in 371 B.C., both Sparta and Athens agreed to a peace but refused to allow Epaminondas to agree to the peace on behalf of the rest of Boeotia.

3. The battle of Leuctra

On the basis of Thebes’ inter-Boeotian imperialism, Sparta and Athens decided to attach Thebes and sent Spartan forces under King Cleombrotos into Boeotia, where outnumbered Theban forces emerged victorious in southern Boeotia near Leuctra, a battle that quickly became one the most famous military engagements of the fourth century (Plutarch, Pelopidas 19-23). The exact details of its battle formations are contested. Modern scholarship has often commended Epaminondas for innovative battle tactics at Leuctra, such as the use of a deep phalanx, an oblique attack, and the integrated use of cavalry. Hanson (1988) has called these innovations into question by analyzing the previous development of these battle tactics over the century preceding Epaminondas.

Nevertheless, the basic canonical view of the battle and its formation runs as follows. Epaminondas set his phalanx in deep rows of fifty men on the left wing directly opposite Cleombrotos’ and his own Spartiate warriors on the right; this tactic pitted the strongest parts of each force’s line against each other. The Sacred Band under Pelopidas was most likely located as a unit “at the head of Epaminondas’ wing” (Beck 2008). Other Boeotians faced the Spartan allies. At the beginning of the battle the Theban cavalry routed the Spartan cavalry and the retreat of the Spartan cavalry into the Spartan line caused confusion. Epaminondas had thus used his cavalry to establish the best atmosphere for an infantry offensive. Pelopidas and the Sacred Band quickly attacked Cleombrotos’ own phalanx before it could reformulate its positions and thus prevented the Spartan line from closing. After hundreds of Spartiates and the king Cleombrotos himself were killed, even more panic ensued, and Sparta ceded to Thebes. Whatever the tactics or innovations used in the battle, the result was clear: the Spartans had been routed by a much smaller force and their reputation – not to mention that of the Thebans -- had been changed irrevocably. Moreover, as Beck notes, Leuctra was the first historical point at which anyone provided successful opposition to Sparta as overseer of the common peace treaty.

Interestingly, in his description of Leuctra, Plutarch preserves a folktale of the suicides of a group of local maidens after their rape by some passing Spartans. This was said to have occurred centuries before the battle of Leuctra. In the tale, the father of the maidens, all sisters, cursed the Spartans for their crime and killed himself over their grave. Plutarch reports that on the eve of Leuctra the maidens’ spirits appeared to Pelopidas in a dream and encouraged the sacrifice of a young female before battle, a victim provided for that following morning by an auburn filly appearing at the perfect moment. Such stories must have proliferated in the centuries following the battle in Boeotia and particularly near Leuctra, where the once-feared Spartan army had met its most crushing defeat. Today a third-century B.C. victory monument (tropaion) marks the site of the battle.

4. Theban "hegemony"

With the Theban victory at Leuctra begins the so-called “Theban hegemony,” or as Buckler notes, a period more aptly titled the “Theban ascendancy,” since Thebes certainly did not directly control many city-states in Greece during this time (Buckler 1980). In fact, one of the most significant aspects of the Theban ascendancy was Thebes’ disinterest in acquiring other states’ territories. Practically speaking, Thebes did not have the manpower to expand in an empirical fashion and thus was forced to rely on other means to gain power, such as diplomatic alliances with other states, which it pursued both in northern and southern Greek areas. In these alliances Thebes smartly maintained a certain amount of control, thereby mitigating much of its own small military size through less tangible means.

Thebes was particularly active in the Peloponnese, whose various states felt emboldened after Leuctra to revolt against and oppose Spartan dominance. Under Epaminondas and Pelopidas in 370-68 B.C. Thebes destroyed much of the northern Peloponnese and helped liberate Messene from Spartan economic and military control. Thebes also helped sponsor the Arcadian League, an anti-Spartan federation of communities, with its new capital Megalopolis. Sparta thus became isolated, surrounded by hostile states, and for the first time in centuries largely insignificant.

Theban hegemony also extended to northern and central Greece. In central Greece, Thebes made defensive alliances with many of the regions surrounding Boeotia, such as Phokis and Euboia. Further north, through diplomacy Pelopidas managed to put Macedonia temporarily under Thebes as a subject-ally and attempted to strengthen the Thessalian state against the tyrant Alexander of Pherai. A complicated period ensued, which included Alexander’s imprisonment of Pelopidas and Pelopidas’ escape with the aid of Epaminondas. In July 364 Pelopidas led a hastily-gathered force to Kynoskephalai to meet Alexander who was still making trouble in Thessaly. Having left Thebes against the advice of the Thebans and under bad omens, and although seriously outnumbered by Alexander’s forces, Pelopidas narrowly carried the battle by regrouping his troops throughout and fighting alongside his hoplites uphill until he himself died. Not incidentally, Beck likens the battle of Kynoskephalai to the battle of Tegyra (375 B.C., see above), which Pelopidas also unexpectedly won in a hastily arranged cavalry and hoplite formation against more numerous forces. The following year, Epaminondas returned to conquer Alexander and make Pherai dependent on Thebes.

The Theban ascendancy saw very few years of real peace within its alliances, for animosities quickly developed among the allies. In 367 B.C. Pelopidas led an allied embassy to Persian Artaxerxes to request a Greek peace with Thebes as broker; the allies, however, almost uniformly repudiated the resultant treaty on the basis of territorial losses or other perceived injuries stipulated. The allies witnessed another failure of a common peace conference the following year in Thebes where Thebes’ own role as leader of the allies was questioned by the Arcadians, who had split into two factions over a regional dispute. In 364 B.C. within Boeotia itself a thwarted coup, intent on establishing an aristocratic government in Boeotia, led to Theban destruction of Orchomenos, the city of the rebels. Finally, in 362 B.C. internal disputes in the Arcadian League led to its collapse and various states within the former league appealed to Sparta and Thebes for help.

5. The battle of Mantinea

Arcadian unrest thus led to the battle of Mantinea (362 B.C.) in which Thebes and Sparta met again, this time in the Peloponnese (Arcadia). Also at this time, perhaps in part on the basis of anti-Theban sentiment remaining from the various peace treaties proposed in previous years, Athens allied with Sparta, as did the Mantineans, Eleans and other small communities. On the Theban side fought the Euboians, Thessalians, Tegeans, Megalopolitans and others. After a short attack on Sparta itself and a skirmish with the Athenians outside Mantinea, Epaminondas led his troops against the Spartans and their full allies. In the battle, the Theban cavalry routed the Spartan phalanx by cutting the phalanx line in half. Theban cavalry were used at the front of the line to protect the hoplite phalanx as well as to raise a dust cloud to hide the visibility of the Theban formation from the Spartan line. As at Leuctra, Epaminondas used a deep phalanx on the left. The Spartans were easily defeated, but Epaminondas was mortally wounded in the front line; his death marked the beginning of a reversal of fortune for Thebes. In his seminal work on the Theban hegemony, John Buckler (1980) quotes Justin, an early Christian apologist (2nd century A.D.), on Epaminondas’ importance for Thebes: “when that leader of the Thebans, just like the head of a javelin, was carried off, the strength of the state was enfeebled; and it seemed not so much to have lost him as to have died with him”. After Mantinea, Thebes never recovered the kind of power it had enjoyed after Leuctra.

6. Causes of Theban decline

It seems clear that Thebes’ decline can in some ways be attributed to the loss of Pelopidas (364) and Epaminondas (362), the two charismatic and experienced men who had led Thebes to its rise but could not assist it in regaining power as its influence waned. There are, however, more complex causes that also contributed to the failure of Thebes to maintain long-lived supremacy in Greece. One of the main factors in the decline of Thebes as a Greek power in the fourth century relates directly to Thebes’ approach to alliance and territorial expansion generally. By focusing more on diplomatic alliance and less on empirical expansion, Thebes managed to rise in power. At the same time, however, Thebes did not pursue a more empirical alliance between all its allies and with itself as designated military leader (hegemon), an alliance between states of the kind that the Greek world had seen in the fifth century under Athens and that was also rising alongside Thebes in the fourth century, with the second Athenian Sea League. This lack of a united umbrella organization wherein all states contributed with ideas and with members to a central congress led to Thebes' own weakening, since it not only left its alliance with no way of developing its common goals, but it also left its disenfranchised allies with their own preoccupations, so much so that ultimately their disagreements with Thebes and with each other led to the end of Thebes’ preeminence. Moreover, during its ascendancy Thebes seemed mostly disinterested in asking its allies to send supporting troops or funds for its various expeditions or in meddling with allied types of government.

A final remark is worth noting. The Sacred Band was destroyed in entirety in the Battle of Chaeroneia (338) by Philip II and Alexander (the Great) who, according to Plutarch, broke the line of the Sacred Band. Ironically, in defeating the Greeks and Thebans at Chaeronea, and thus in ending Greek supremacy, Philip II relied on the very battle tactics he had reputedly learned from Epaminondas and which the Theban had used at the battles of Leuctra and Mantineia