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How did Thebes rise to break Spartan power at Leuctra, and why did its hegemony collapse at Mantinea in 362 BC?

The liberation of Thebes in 379 BC and the rise of Boeotia, Epaminondas and Pelopidas and the Sacred Band, the tactical revolution and the defeat of Sparta at Leuctra in 371 BC, the liberation of Messenia and the founding of Megalopolis, the brief Theban hegemony, and the Battle of Mantinea in 362 BC

A focused answer to the HSC Ancient History dot point on Greece from the liberation of Thebes in 379 BC to Mantinea in 362 BC. The rise of Boeotia under Epaminondas and Pelopidas, the Sacred Band, the oblique-phalanx victory at Leuctra, the liberation of Messenia, and the brief, exhausting Theban hegemony.

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Quick answer

Between 379 and 362 BC Thebes rose from a Spartan-garrisoned client to the first power in Greece and back again. The liberation of 379 BC (led by Pelopidas), the professional Sacred Band, and Epaminondas's tactical revolution culminated at Leuctra in 371 BC, where a massed, oblique left wing shattered the Spartan army, killed King Cleombrotus, and destroyed the myth of Spartan invincibility. Epaminondas then invaded the Peloponnese, freed the Messenian helots and founded Messene (369 BC) and Megalopolis (c. 368 BC), permanently crippling Sparta. But the hegemony rested on two men; Pelopidas died in 364 BC, and at Mantinea in 362 BC Epaminondas won the field but was killed, leaving Greece, in Xenophon's words, in even greater confusion than before - an exhausted, leaderless vacuum that Philip II of Macedon would fill.

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What this dot point is asking

NESA expects you to trace how Thebes rose from a garrisoned client of Sparta to the leading power in Greece, and then fell back, across the years 379 to 362 BC. You need the liberation of 379 BC, the reforms and personalities (Epaminondas, Pelopidas, the Sacred Band), the tactical revolution and the defeat of Sparta at Leuctra in 371 BC, the strategic consequences (the invasions of the Peloponnese, the liberation of Messenia, the founding of Megalopolis), the brief hegemony, and the Battle of Mantinea in 362 BC. Above all you must argue causation, change and significance, not just narrate the battles.

In plain English

Picture a neighbourhood that one big, tough family has bossed for generations, mainly because everyone was scared of them and nobody had ever beaten them in a straight fight. Then a smaller family throws off that family's minder, trains a small squad of full-time specialists, and, led by a clever tactician, does the unthinkable in one afternoon (Leuctra) - it beats the tough family fair and square and even kills their leader. The fear evaporates. The smaller family then goes further and takes away the farmland the tough family lived off (Messenia), which finishes them for good. But the clever tactician is really the whole show. When he wins his last fight but is killed doing it (Mantinea), his family has nothing to fall back on, the whole street is left exhausted and leaderless, and soon a newcomer from up the road (Macedon) walks in and takes over.

The answer

The liberation of Thebes (379 BC)

In 382 BC a Spartan officer, Phoebidas, seized the Cadmeia (the Theban acropolis) in peacetime while marching through, and installed a Spartan garrison propping up a narrow pro-Spartan oligarchy under Leontiades. This was a naked breach of the King's Peace of 387/6 BC (which guaranteed the autonomy of Greek states) and became the great symbol of Spartan arrogance in the years of its hegemony.

In midwinter 379 BC a band of Theban democratic exiles who had taken refuge in Athens, led by Pelopidas, returned in disguise, assassinated the oligarchic leaders (Leontiades and the polemarch Archias) in a coordinated night coup, and raised the citizens. The isolated Spartan garrison on the Cadmeia, cut off and unsupported, surrendered and withdrew under truce. Thebes was free, its democracy restored, and the Boeotian League re-formed under Theban leadership. The liberation put Thebes and Sparta on a direct collision course.

The rise of Boeotia and the Sacred Band

Two men drove the Theban revival. Pelopidas was the daring commander of the coup and, later, of the elite corps. Epaminondas was the strategist and one of the seven boeotarchs (the elected magistrate-generals of the federal Boeotian League), a man Roman and Greek tradition alike remembered as the finest general and statesman of his age.

Around 378 BC Thebes raised the Sacred Band (Hieros Lochos), an elite standing corps of 300 hoplites, traditionally 150 pairs of male lovers, first organised (says Plutarch) by Gorgidas and later led as a single striking unit by Pelopidas. Unlike the ordinary citizen levy, it was permanent and professionally drilled. In 375 BC Pelopidas used it at Tegyra to defeat a larger Spartan force in the open, an early crack in the Spartan reputation and a rehearsal for what was to come. Through the 370s the Boeotian League expanded and consolidated, absorbing or coercing the other Boeotian towns under Theban direction.

The road to Leuctra (the peace conference of 371 BC)

In 371 BC a general peace conference met at Sparta to renew the King's Peace. Epaminondas insisted on swearing the oath for the whole Boeotian League rather than for Thebes alone, since Thebes now spoke for a federal state. The Spartan king Agesilaus II, Thebes's implacable enemy, refused, and struck Thebes from the treaty, effectively declaring it an outlaw. Within about three weeks the Spartan king Cleombrotus I, already in Phocis with an army, marched into Boeotia. The two forces met at Leuctra, southwest of Thebes near Thespiae.

The Battle of Leuctra (371 BC) - the oblique phalanx

Epaminondas was outnumbered (perhaps 6,000 to 7,000 Boeotians against a Peloponnesian army of around 10,000 hoplites), and the Theban command was divided over whether to fight at all. He carried the vote and then fought the battle in a way that broke every convention.

Greek armies traditionally placed their best troops on the right wing, and phalanxes were normally eight to twelve shields deep. Epaminondas reversed both. He massed his best men, the Thebans and the Sacred Band, on the left, in a column at least fifty shields deep (Xenophon, Hellenica 6.4.12), placed directly opposite King Cleombrotus and the Spartiate elite on the Spartan right. The rest of his line he set in an oblique (echeloned) order, held back or "refused" so it would not engage until the decisive wing had done its work. A superior Boeotian cavalry screen first drove the Spartan horse back into their own still-forming ranks, sowing disorder. Then Pelopidas launched the Sacred Band in a rapid charge, and the deep Theban column smashed the Spartan right where its strength and its king stood.

The myth of Spartan invincibility shattered

Leuctra was a psychological earthquake. For the first time a full Spartan army had been beaten decisively in a fair, pitched hoplite battle, and a reigning Spartan king had been killed in the field. The Spartiate losses (around 400 of only 700 present) also laid bare the demographic crisis of oliganthropia, the long decline in the citizen body that meant Sparta simply could not replace such losses. The aura that had sustained Spartan hegemony since the Persian Wars was gone in an afternoon, and with it the assumption that Sparta could enforce the King's Peace.

The invasions of the Peloponnese and the liberation of Messenia

Epaminondas did not stop at victory. In the winter of 370/369 BC he led a large army (Thebans, Arcadians, Argives and others) into the Peloponnese, the first time in memory a hostile army had penetrated Laconia and looked on the unwalled city of Sparta itself. Agesilaus held the city, but Spartan prestige was broken.

The decisive stroke was the liberation of Messenia. Epaminondas freed the Messenian helots and founded the great fortified city of Messene beneath Mount Ithome in 369 BC, recalling Messenian exiles from across the Greek world to people it. This was the blow that finished Sparta as a great power. Spartan society had rested for centuries on the helots of Messenia, whose forced agricultural labour freed the Spartiates to be full-time soldiers. Cut that away, and Sparta lost roughly half its land and workforce at a stroke. A lost battle can be recovered; the loss of Messenia was permanent, and Sparta never regained its rank.

The founding of Megalopolis and the Arcadian League

To hem Sparta in from the north, the Thebans backed the unification of the Arcadian towns into a federal Arcadian League with a new purpose-built capital, Megalopolis ("the great city"), founded around 368 BC. Together with Messene it formed a ring of hostile, fortified states penning Sparta into Laconia. Spartan power, which had radiated across the Peloponnese for two centuries, was now boxed into its home valley.

The brief Theban hegemony

For roughly a decade Thebes was the first power in Greece. Pelopidas extended Theban influence north into Thessaly (checking the tyrant Alexander of Pherae) and even secured a favourable Persian rescript in 367 BC that recognised Theban leadership and Messenian independence. But Theban dominance was thin. Thebes had neither the population and fleet of Athens nor the old alliance network of Sparta. It rested on its army and, above all, on two men. Pelopidas was killed in 364 BC fighting Alexander of Pherae at Cynoscephalae. The Peloponnesian allies who had welcomed Theban help against Sparta, the Arcadians especially, soon resented Theban domination and split, some siding with Sparta and Athens. The hegemony was already fraying.

The Battle of Mantinea (362 BC) - victory and death

In 362 BC Epaminondas marched into the Peloponnese a final time to hold the Theban position, facing a coalition of Sparta, Athens, Mantinea, Elis and others, while Tegea, the Messenians and the Argives stood with Thebes. At Mantinea he again used the oblique attack, massing and leading his left in a column against the enemy line, and broke through. But at the moment of victory he was struck by a spear and mortally wounded. The Thebans, leaderless, did not press the advantage, and the battle ended indecisively. Tradition (Cornelius Nepos, Plutarch) has the dying Epaminondas, told he left no son, reply that he left two daughters, "Leuctra and Mantinea," his victories, and urge the Thebans to make peace.

The power vacuum Macedon would fill

Mantinea settled nothing. As Xenophon ends his Hellenica, the battle produced "even more confusion and uncertainty in Greece than there had been before." Sparta was crippled, Thebes had won the field but lost the one man who was its hegemony, and Athens was in no position to lead. A Common Peace followed (362/361 BC) that Sparta refused to join because it would not recognise free Messenia. Greece was fragmented, exhausted and leaderless. Into precisely this vacuum stepped Philip II of Macedon, who came to power in 359 BC, had spent time as a hostage in Thebes and learned its military lessons, and within a generation imposed his own supremacy at Chaeronea in 338 BC.

How to read a source on this topic

Section IV sources on this period are dominated by three ancient writers, and the first skill is to weigh their bias.

First, Xenophon's Hellenica is the contemporary narrative, but he was a friend of Sparta and of King Agesilaus. His account is coloured by that sympathy, and, most tellingly, he passes over the founding of Messene and Megalopolis in near silence, events fatal to Sparta that he could not bring himself to dwell on. Treat his SILENCES as evidence, not just his statements.

Second, Diodorus Siculus (Book 15), writing in the first century BC but drawing on the fourth-century historian Ephorus, gives a fuller and more balanced narrative and is more generous to Epaminondas. He is later and sometimes muddled on detail, so corroborate his chronology.

Third, Plutarch's Pelopidas (and his Agesilaus) is a moralising biography, not a history, written centuries later, but it preserves material on the Sacred Band, Tegyra and the personalities. Read it for character and detail, but check its facts against the historians.

For any source, work through content (what it shows), reliability (author, date, motive, genre), usefulness (what it can and cannot tell a historian), and perspective (whose side it takes, and what it leaves out).

Historians on the Theban hegemony

Xenophon supplies the frame of a Greece sliding into disorder, but his pro-Spartan perspective and his silence on Messenia must be read critically. Diodorus, through Ephorus, offers the constructive counter-narrative of Theban achievement. Among moderns, John Buckler (The Theban Hegemony, 371-362 BC, 1980) wrote the standard study, arguing that the hegemony was a coherent and rational, if short-lived, achievement built around Epaminondas rather than a mere accident of one battle. George Cawkwell ("Epaminondas and Thebes", Classical Quarterly, 1972) credits Epaminondas's strategic vision while stressing the structural limits of Theban power. Paul Cartledge (Agesilaos and the Crisis of Sparta, 1987) traces how Leuctra and the loss of Messenia dismantled the Spartan state and reshaped the whole Greek system. Victor Davis Hanson has emphasised the boldness of Epaminondas's invasions of the Peloponnese and the ravaging of Spartan power as a new kind of decisive strategy. Use these as competing emphases (Xenophon's decline, Buckler's coherent hegemony, Cartledge's crisis of Sparta) rather than a list of names.

Model exam responses

1. Source-analysis response. "Source A, an ExamExplained reconstruction of a later tactician's sketch of Leuctra, is useful for showing the two features that made Epaminondas's method revolutionary: the extreme depth of the left wing (around fifty shields, against a norm of eight to twelve) and the oblique, refused alignment of the rest of the line, so that overwhelming force struck one point first. Its usefulness is limited by being an illustrative reconstruction rather than a contemporary document, so a historian would corroborate it against Xenophon's statement (Hellenica 6.4.12) that the Thebans were 'not less than fifty shields deep', and against Diodorus's fuller account. Read alongside those, it supports the argument that Leuctra was won by design, not luck, and that Epaminondas deliberately targeted the Spartan king and his best troops."

Marker's note: the response uses the source's specific detail (depth, oblique order), states the limitation of the source type, and corroborates with a named ancient source rather than merely describing the sketch.

2. Essay paragraph (significance of the liberation of Messenia). "The stroke that turned a Theban victory into the permanent ruin of Sparta was not Leuctra itself but the liberation of Messenia in 369 BC. Spartan society had rested for two centuries on the forced labour of the Messenian helots, whose agricultural surplus freed the Spartiates to train as full-time soldiers. By freeing those helots and planting the fortified city of Messene beneath Mount Ithome, Epaminondas cut away roughly half of Sparta's land and workforce at a single stroke. As Cartledge argues, this converted the military defeat at Leuctra into a structural crisis of the Spartan state, because a lost battle can be recovered but a lost economic base cannot. Sparta, already crippled by oliganthropia, never again fielded a first-rank army. It was Messenia, more than the battlefield, that ended Sparta as a great power."

Marker's note: this paragraph scores because it argues significance (why Messenia mattered MORE than the battle), ties the claim to precise evidence (369 BC, the helot economy), and integrates a named historian as argument rather than decoration.

3. Short-answer response (command word: "explain"). "Epaminondas's death at Mantinea in 362 BC was decisive because the Theban hegemony had always rested on him personally rather than on durable institutions. Having broken the enemy line with his usual oblique attack, he was killed at the point of victory, and his leaderless army failed to exploit the win, so a tactical success produced no strategic result. Because Thebes lacked the fleet, revenue and alliance system to sustain leadership without him, his death, rather than any defeat, dissolved the hegemony and, as Xenophon notes, left Greece in even greater confusion than before."

Marker's note: markers reward the explicit causal chain (personal basis of power, death at the moment of victory, no exploitation, dissolution) rather than a narrative of the battle.

Command words and technique

"Explain" wants a causal mechanism (X caused Y, because Z), not two descriptions side by side. "Assess" / "to what extent" / "evaluate" demand a sustained verdict, stated in your introduction and defended in every paragraph; for a 20 to 25-mark essay, plan a one-line thesis plus three or four argument lines before you write. On this period, the sharpest marks come from handling SOURCE BIAS as argument: point out that Xenophon's pro-Spartan sympathy and his silence on Messene and Megalopolis are themselves evidence, and set Diodorus and modern historians (Buckler, Cartledge) against him. Weave historiography INTO the argument ("Buckler reads the hegemony as coherent, but Cawkwell's stress on its structural limits qualifies this") rather than listing names at the end.

Practice questions

Original practice questions graded from foundation to exam level, each with a full worked solution. Try them before revealing the solution.

foundation4 marksOutline the liberation of Thebes in 379 BC and its immediate significance.

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A 4-mark "outline" wants the event sketched with its cause and consequence, not a single sentence.

The background: Since 382 BC a Spartan garrison had held the Cadmeia (the Theban acropolis), installed after a Spartan officer, Phoebidas, seized it in peacetime and propped up a narrow pro-Spartan oligarchy under Leontiades. This was a flagrant breach of the King's Peace of 387/6 BC and became a symbol of Spartan overreach.
The event: In midwinter 379 BC a group of Theban democratic exiles based in Athens, led by Pelopidas, slipped back into the city, killed the oligarchic leaders (Leontiades and Archias) in a coordinated coup, and roused the citizens. The isolated Spartan garrison on the Cadmeia surrendered and was allowed to withdraw.
The significance: The liberation restored Theban independence, re-founded the democratic Boeotian League under Theban leadership, and set Thebes and Sparta on the collision course that led to Leuctra. Markers reward the garrison, the coup led by Pelopidas, and the link forward to the coming war.

foundation3 marksDescribe the Sacred Band and explain why it mattered militarily.

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A 3-mark "describe and explain" needs the unit's nature plus its function.

What it was. The Sacred Band (Hieros Lochos) was an elite Theban corps of 300 hand-picked hoplites, traditionally formed of 150 pairs of male lovers, raised around 378 BC and reportedly first organised by Gorgidas. Unlike a citizen levy called up for a campaign, it was a standing, state-maintained professional unit.

Why it mattered. As a permanent, drilled shock force it gave Theban commanders a reliable spearhead. Pelopidas used it to win at Tegyra in 375 BC against a larger Spartan force, and at Leuctra in 371 BC it struck the Spartan right at the decisive moment. It embodied the new Theban military professionalism that ended Spartan dominance.

Markers reward the composition (300, elite, standing unit) and a concrete battlefield role.

core6 marksSource A is an ExamExplained reconstruction of the kind of battlefield sketch a later tactical writer might draw of Leuctra (371 BC). It shows the Boeotian left wing massed in a deep column around fifty shields deep, headed by a small elite block, set diagonally against the Spartan right where the king and his best troops stood, while the rest of the Boeotian line is drawn back from the enemy. Using Source A and your own knowledge, explain Epaminondas's tactics at Leuctra.

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A 6-mark "explain with a source" needs the source read explicitly, then own knowledge developing the mechanism.

Use the source: Source A illustrates the two innovations usually credited to Epaminondas. First, the massed depth on the LEFT (around fifty shields deep, against a Greek norm of eight to twelve), concentrating overwhelming weight at one point. Second, the diagonal, or oblique, alignment with the rest of the line "refused" (held back), so the strengthened wing struck first while the weaker wing stayed out of contact. The small elite block heading the column is the Sacred Band.
Own knowledge - the reversal of custom: Convention placed a general's best troops on the RIGHT. Epaminondas instead loaded his LEFT, directly opposite King Cleombrotus and the Spartiates on the Spartan right, so that if the elite Spartan wing broke, the whole army would unravel.
Own knowledge - the combined arms and the result: A superior Boeotian cavalry screen first drove the Spartan horse back into their own forming infantry, adding to the disorder. Pelopidas then launched the Sacred Band in a rapid charge, and the deep column crushed the Spartan right. Cleombrotus was killed and around 1,000 Lacedaemonians fell, including roughly 400 of the 700 Spartiates present.

Markers reward explicit use of the source's two features (depth and the oblique/refused line) plus own-knowledge development of the reversal of the right-wing custom and the combined-arms sequence.

core5 marksExplain how the liberation of Messenia after Leuctra permanently weakened Sparta.

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A 5-mark "explain" needs the causal mechanism, not just the events.

The event: In the winter of 370/369 BC Epaminondas invaded the Peloponnese and detached Messenia from Sparta, freeing the Messenian helots and founding the fortified city of Messene beneath Mount Ithome in 369 BC, populated by returning Messenian exiles.
Why it was fatal, not just damaging: Spartan society rested on the helot system. Messenia, conquered in the eighth and seventh centuries BC, supplied the agricultural surplus that freed Spartiates to be full-time soldiers. Removing Messenia at a stroke cut Sparta's economic base and its helot workforce roughly in half.
The compounding factor: This struck a state already suffering oliganthropia (a shrinking citizen body). With fewer Spartiates and now far less land, Sparta could no longer field or fund a first-rank army. Unlike a lost battle, the loss of Messenia was permanent, and Sparta never recovered its great-power status.

Markers reward the LINK between the helot economy and Spartan military power, and the point that this loss was structural and irreversible, not merely a defeat.

core6 marksExplain why the Battle of Leuctra (371 BC) is regarded as a turning point in Greek history.

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A 6-mark "explain why" needs several developed reasons tied to the question of significance.

It shattered the myth of Spartan invincibility: For the first time a full Spartan army was beaten decisively in a pitched hoplite battle on open ground, and a Spartan king (Cleombrotus) was killed in the fighting. The psychological aura that had underpinned Spartan hegemony since the Persian Wars was broken in a single afternoon.
It ended Spartan hegemony: The King's Peace system had rested on Spartan power to enforce it. After Leuctra, Sparta could no longer dominate central Greece or hold its alliance together, and Thebes replaced it as the leading land power.
It opened the way to Messenia's liberation: The defeat exposed the Peloponnese. Within a year Epaminondas had invaded Laconia, freed Messenia, and founded Megalopolis, permanently crippling Sparta.
It demonstrated a tactical revolution: The oblique order and massed wing showed that drill, concentration and command could overturn the Spartan reputation for hoplite supremacy, a lesson later students of war (down to Frederick the Great at Leuthen) drew on.

Markers reward the reputation, the collapse of hegemony, the strategic consequences for Sparta, and the tactical significance, rather than a narrative retelling of the battle.

exam20 marksESSAY. Assess the extent to which Epaminondas was responsible for both the rise and the fall of Theban hegemony.

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A band-6 essay for a 20-mark "assess the extent" needs a clear verdict, argument lines tied to dated evidence, a counter-view, and named historiography. This is a plan plus a model paragraph.

Thesis: Epaminondas was the indispensable architect of Theban hegemony, its victory at Leuctra, its strategic reordering of the Peloponnese, and its final battle, but the hegemony's fragility was structural, so his death at Mantinea in 362 BC exposed weaknesses he alone had masked rather than solved.
Argument line 1 - the rise was largely his work: Epaminondas designed and won Leuctra (371 BC) through the oblique order and massed left, killing Cleombrotus. He then led the invasions of the Peloponnese, freed Messenia (Messene founded 369 BC), and backed Megalopolis (c. 368 BC), converting a battlefield win into a permanent strategic settlement against Sparta.
Argument line 2 - but the hegemony rested on too narrow a base: Thebes lacked the population, fleet and revenue of Athens or the old Spartan alliance system. Its dominance depended on a handful of gifted commanders and on fear of its army, not on durable institutions or willing allies, many of whom (Arcadians, Athenians) soon turned against it.
Argument line 3 - his death was decisive: At Mantinea (362 BC) Epaminondas again won the field but was killed, and, as Xenophon stresses, Greece was left in "greater confusion and uncertainty than before." That a single death could dissolve the hegemony shows how far it had been carried by one man.
Counter-argument: Pelopidas (Tegyra 375 BC, the liberation of 379 BC, Thessalian and Persian diplomacy) shared the achievement, and impersonal factors (Spartan oliganthropia, war-weariness) shaped both rise and fall independently of Epaminondas.
Historiography: Xenophon's Hellenica is coloured by pro-Spartan sympathy and pointedly omits the founding of Messene and Megalopolis, so his silence must be read critically. Diodorus (Book 15), drawing on Ephorus, is more favourable to Epaminondas. John Buckler (The Theban Hegemony, 371-362 BC, 1980) argues the hegemony was a coherent, if short-lived, achievement centred on Epaminondas. George Cawkwell stresses both his genius and the structural limits of Theban power.
Model paragraph (argument line 3): Epaminondas's death at Mantinea is the clearest measure of how personal the hegemony was. Having once more arranged his army obliquely and broken the Spartan-led coalition, he was struck down at the moment of victory, and the Thebans, in Diodorus's account, halted rather than exploit the win. Xenophon closes his history by observing that the battle produced not a settlement but "even more confusion and uncertainty in Greece than before." A hegemony that could win its last battle and yet dissolve because one commander fell was never institutionally secure. Epaminondas had supplied the leadership, the tactics and the strategic vision that Thebes itself could not replace, which is precisely why his death, rather than any defeat, ended the Theban moment.

Marker's note: band 6 responses commit to a genuine "extent" verdict (architect of the rise, but the fall was structural and his death merely exposed it), use dated evidence, handle Xenophon's bias, and weave at least two historians as argument rather than a list.

exam25 marksESSAY. To what extent did the Theban hegemony leave Greece weaker and create the conditions for the rise of Macedon?

Show worked solution →

A band-6 essay for a 25-mark "to what extent" needs a balanced verdict, developed argument lines, a counter-view, and named historiography. This is a plan plus a model paragraph.

Thesis: The Theban hegemony substantially weakened Greece by destroying Spartan power without building a stable replacement, leaving a fragmented, exhausted and leaderless Greece after 362 BC, but Macedon's rise also owed much to Philip II's own reforms, so Theban policy created the opening rather than the outright cause.
Argument line 1 - Thebes broke the old order: Leuctra (371 BC) and the liberation of Messenia (369 BC) permanently crippled Sparta and dismantled the King's Peace balance. The one power that had ordered the Greek states for a generation was reduced to a second-rank polis unable to lead.
Argument line 2 - but Thebes built nothing lasting in its place: Theban dominance rested on its army and on Epaminondas, not on a durable alliance. After Mantinea (362 BC) no state could impose order. Xenophon ends his Hellenica on exactly this note, that Greece was left in "greater confusion and uncertainty than before."
Argument line 3 - the vacuum favoured Macedon: Into this exhaustion stepped Philip II (from 359 BC), who had spent time as a hostage in Thebes and studied its methods. His reformed army, drawing on Theban lessons of concentration and professional infantry, met no united Greek resistance and prevailed at Chaeronea in 338 BC.
Counter-argument: Macedon's rise was not inevitable from Theban policy. Philip's own diplomacy, gold, sarissa phalanx and persistence, plus continued Athenian and Theban disunity, were decisive; a more capable Greek response could still have checked him. The vacuum was necessary but not sufficient.
Historiography: Xenophon's pro-Spartan Hellenica frames the period as descent into disorder and is silent on Theban constructive achievements. Diodorus (Book 15), via Ephorus, is fuller and more sympathetic. John Buckler (The Theban Hegemony, 371-362 BC, 1980) sees a real but unsustainable settlement. Cartledge (Agesilaos and the Crisis of Sparta, 1987) traces how the destruction of Spartan power reshaped the whole Greek state system that Philip then exploited.
Model paragraph (argument line 2): The Theban achievement was almost entirely negative in its lasting effect, brilliant at demolition, incapable of construction. Epaminondas could win Leuctra, ravage Laconia and plant Messene and Megalopolis as anti-Spartan bulwarks, yet Thebes never turned military dominance into an institutional order that other states would accept. Its former allies, the Arcadians and the Athenians, were fighting against it by Mantinea, and its supremacy depended so wholly on one commander that his death dissolved it. As Xenophon observed, the result was not peace but deeper confusion. Thebes had removed the keystone of the old order without replacing it, and it was this leaderless exhaustion, more than any single Theban act, that left the door open for Philip.

Marker's note: band 6 responses reach a nuanced verdict (Thebes created the opening, Philip's own agency completed the process), use dated evidence across 371 to 338 BC, handle Xenophon's silences, and integrate historians as competing weightings.