The Delian League (478–465 BC): how an alliance became the Athenian empire

In 479 BC the Persian invasion of Greece was over, but the war was not. The Greeks of the islands and the coast of Asia Minor were free for the moment, with a Persian empire just across the water. Within two years they had formed a new alliance with its treasury on the sacred island of Delos and Athens at its head. Within twenty years that alliance had become something else: an Athenian empire that kept its members in by force.

Where this chapter fits

This chapter opens the fourth and last part of the Persian Wars, the Greek counterattack. In the previous chapter the Greeks defeated the Persian army at Plataea and the Persian camp and fleet at Mycale, in the summer of 479 BC. After Mycale the allies argued at Samos about what to do with the Greeks of Ionia. The Peloponnesians wanted to move them to Greece, onto the land of the Greeks who had sided with Persia; the Athenians refused to let Sparta decide the fate of their colonists, and the islanders were taken into the alliance instead.

That quarrel showed where the alliance of 481 BC would split. Sparta led the Greeks on land and had little interest in a long war overseas. Athens had the largest fleet, the strongest ties with the Ionians, and every reason to keep the Persians far from the Aegean. The years that followed, which the Greeks later remembered as the time between the Persian war and the war between Athens and Sparta, are told in detail by only one historian, Thucydides, who wrote that his predecessors had left them out.1

Untangled History · from Mycale to the Athenian empire, 479–465 BC

Winter 479/478 BCSestosThe Athenians besiege and take Sestos on the Hellespont.

478 BCCyprus and ByzantiumPausanias leads the allied fleet; the allies turn against him.

478/477 BCThe LeagueAllies meet on Delos; Aristides assesses ships and money.

c. 476 BCEionCimon takes the Persian fort on the Strymon.

c. 475 BCScyrosPirates expelled, the island settled; Theseus’ bones brought home.

c. 470 BCNaxosThe first ally to leave is besieged and forced back.

c. 470 BCExilesPausanias dies in Sparta; Themistocles flees to Persia.

c. 466–465 BCEurymedon and ThasosA great victory over Persia, then another revolt.

Order of events after Thucydides 1.89–1.100. Thucydides gives the order but almost no dates; the years after 478 BC are approximate modern reconstructions.

The siege of Sestos

From Mycale the allied fleet sailed north to the Hellespont to destroy Xerxes’ bridges, and found them already broken. The Spartan king Leotychidas and the Peloponnesians decided to go home. The Athenians under Xanthippus, the father of Pericles, stayed with the Ionians and the Greeks of the Hellespont and laid siege to Sestos, the strongest fortress on the European shore of the straits.2 Thucydides tells the same story in one sentence: the Athenians and the allies from Ionia and the Hellespont “remained and laid siege to Sestos, which was still held by the Medes”, wintered before it and took it when the defenders left.3

Herodotus fills the siege with detail. The Persian governor of the region, Artayctes, had plundered the shrine of the hero Protesilaus at nearby Elaeus, and the local Greeks hated him for it. By the autumn the defenders were so short of food that they boiled the leather straps of their beds and ate them. Then the Persians slipped out by night; the next morning the people of the Chersonese signalled from the towers and opened the gates. Artayctes was caught, and the Athenian general refused his offer of a ransom. On the headland where Xerxes had bridged the strait, the Athenians nailed him to boards and hanged him, and stoned his son before his eyes.

With that Herodotus ends his history. The Athenians sailed home in 478 BC carrying the cables of Xerxes’ bridges, to be dedicated in their temples. For the next fifty years we depend on Thucydides, on scattered inscriptions, and on writers who lived centuries later.

Pausanias at Cyprus and Byzantium

In 478 BC the allies were still led by Sparta. The Spartans sent Pausanias, the victor of Plataea, to command the fleet, with twenty ships from the Peloponnese, thirty from Athens and others from the allies. He sailed first to Cyprus and freed most of the island from Persian rule, then turned north and forced the Persian garrison of Byzantium to surrender. Diodorus, writing four centuries later, gives slightly different numbers: fifty ships from the Peloponnese and thirty from Athens under Aristides.4

Byzantium controlled the passage between the Black Sea and the Aegean, and its capture should have been the high point of Pausanias’ career. Instead it began his fall. According to Thucydides, Pausanias secretly released some of the king’s relatives captured in the city and sent them home to Xerxes, together with a letter: “I propose also, with your approval, to marry your daughter, and to make Sparta and the rest of Hellas subject to you.”5 Xerxes answered by sending Artabazus, a general who had fought at Plataea, to take over the province of Dascylium on the Hellespont and act as go-between.

Whatever the truth of the letters, the allies saw a change in Pausanias. He began to dress like a Persian, travelled through Thrace with a bodyguard of Medes and Egyptians, kept a Persian table, and treated the allied captains with such violence that no one could approach him. To Thucydides there had been in him “more of the mimicry of a despot than of the attitude of a general”.6

WORD Hegemony. From the Greek hegemonia, “leadership”. In 478 BC it meant the right to command a common army or fleet, which Sparta had held since 481 BC. The question in these years was who would hold the hegemonia at sea, and what that would come to mean.

The allies turn to Athens

The Ionians and the newly freed islanders went to the Athenians and asked them, as their kinsmen, to become their leaders and to protect them from Pausanias. The Athenians agreed. Plutarch, writing about AD 100, tells a dramatic version: two captains, Uliades of Samos and Antagoras of Chios, rammed Pausanias’ own flagship near Byzantium, told him to thank the luck that had fought for him at Plataea, and sailed off to join the Athenians.7

Sparta recalled Pausanias to answer the accusations. He was cleared of the gravest charges, but he was not sent back. A new Spartan commander, Dorcis, arrived with a small force and found that the allies would no longer accept Spartan leadership; he went home, and Sparta sent no one else. Thucydides gives the Spartans’ reasons: they feared that other commanders abroad would go the way of Pausanias, they wanted to be rid of the war against Persia, and they thought the Athenians capable of leading it and, for the moment, friendly. The nineteenth-century historian George Grote saw the new alliance in the same light: it was the islanders’ fear of Persia, more than Athenian ambition, that created it.

The low island of Delos in the Aegean, with ancient ruins along the shore — Delos today. The small sacred island of Apollo became the meeting place and treasury of the new alliance. Photo: Leonora Enking, CC BY-SA 2.0, Wikimedia Commons.

An alliance on Delos

The new alliance was founded in the winter of 478/477 BC. Its members were the cities of the Aegean islands, of Ionia and Aeolis on the coast of Asia Minor, and of the Hellespont, under Athenian leadership. Its stated purpose, in Thucydides’ words, was “to retaliate for their sufferings by ravaging the King’s country”: to carry the war into Persian territory and to keep the Persians out of the Aegean.8 Modern historians usually date the founding to 478/477 BC; some sources simply give 478 BC.9

The alliance had no name of its own. Modern historians call it the Delian League, after its centre. Delos was an obvious choice: a small island in the middle of the Cyclades, sacred to Apollo, with an old festival that had once brought the Ionian Greeks together. The treasury of the League was kept in the temple, and the members met there in a common congress. Thucydides stresses that at first Athens led “independent allies who acted on the resolutions of a common congress”.

The members swore to keep the alliance for ever. Plutarch says Aristides administered the oath for the Athenians and threw lumps of red-hot iron into the sea, calling down curses on anyone who broke the vow: the alliance was to last until the iron floated.10

FACT Until the iron floats. Throwing lumps of iron into the sea made an oath permanent: it would hold until they rose to the surface again. Plutarch reports the ceremony (Life of Aristides), and adds that later, when Athens ruled the allies more harshly, Aristides told the Athenians to let the perjury fall on him.

Archaic marble lions lining the sacred way on Delos — The Terrace of the Lions on Delos, set up in the 7th–6th century BC; the delegates of the League would have walked past them. Photo: Ggia, CC BY-SA 3.0, Wikimedia Commons.

Ships or money: the first assessment

A fleet costs money, and every member had to contribute. The Athenians decided which cities would provide ships and which would pay money instead. They created a new board of Athenian officials, the “Treasurers for Hellas”, to receive the money, which was called the phoros. The first total, according to Thucydides, was 460 talents.

The task of fixing each city’s share fell to Aristides, the Athenian commander whom the allies trusted most. Plutarch says he travelled round, surveyed each city’s land and revenue, and set the amounts so fairly that the allies later remembered his assessment as a golden age; he went out poor and came back poorer. Plutarch gives the same total as Thucydides, 460 talents. Diodorus, writing much later, says 560.11

Modern historians have long debated whether the first assessment really came to 460 talents. Some think that figure is too high for the money paid in the first years and may include the value of the ships that many allies supplied instead; others defend Thucydides’ figure.12 13

Untangled History · the tribute of the League, in talents

First assessment, 478/477 BC (Thucydides, Plutarch)460 talents

First assessment, as Diodorus gives it560 talents

Average yearly tribute, 431 BC (Thucydides 2.13)600 talents

Raised after Pericles’ death (Plutarch)1,300 talents

Thucydides 1.96 and 2.13; Diodorus 11.47; Plutarch, Life of Aristides. Ancient figures; modern historians debate the first one. A talent was a weight of about 26 kg of silver.

WORD Phoros. The Greek word for the allies’ payments, literally “that which is brought”. Grote noted that the name seems to have come into use with the League and carried no shame at first, but later became so odious that it was replaced by a milder word. Modern historians translate it as “tribute”.

Cimon’s campaigns: Eion, Scyros and Carystus

The League’s first commander was Cimon, son of Miltiades, the victor of Marathon. His first target was Eion, a Persian fortress at the mouth of the river Strymon in Thrace. Thucydides says only that the Athenians besieged and took it and enslaved its people. Plutarch adds that Cimon cut off the town’s supplies by driving the Thracians from the land around it, until the Persian commander Boges, whom Plutarch calls Butes, set fire to the town and burned himself and his family rather than surrender. The translator of Diodorus dates the capture of Eion to 476 BC.14

Next came Scyros, a rocky island in the Aegean whose inhabitants, Dolopians, lived by piracy. The Athenians enslaved them and settled the island with their own colonists. Then the League turned on Carystus, a city at the southern tip of Euboea that the Greek fleet had already ravaged in 480 BC for taking the Persian side; it was forced to surrender on terms. Diodorus compresses all these campaigns into a single year, which his translator notes is wrong by about ten years.

Untangled History · the Delian League, 478–465 BC

Map of the Aegean showing Athens, Delos, the allied islands and Ionian cities, the places the League took from Persia, and the cities forced into or kept in the League

AthensDelos (treasury)NaxosCarystusScyrosEionThasosSestosByzantiumLesbosChiosSamosMiletusSardis (Persian)Cyprus and the Eurymedon →
further east, off the map

Athens and early alliesLeague treasuryTaken from PersiaForced in, or kept in by force

A selection of places named by Thucydides 1.94–1.101, Herodotus 9.106 and 9.114–121. Schematic; dot positions approximate.

The bones of Theseus

The conquest of Scyros had a religious sequel that made Cimon famous at home. According to legend, Theseus, the hero-king of Athens, had died on Scyros, murdered by its king Lycomedes. Plutarch says an oracle had told the Athenians to bring home his bones, but the islanders had never let them search. After the conquest Cimon found a grave, carried the remains onto his ship, and brought them to Athens with great ceremony, about four hundred years after Theseus was said to have left the city. Pausanias, who travelled in Greece in the second century AD, also credits Cimon with finding the bones.15

The story mattered in Athens. Theseus was the hero who was believed to have united Attica, and bringing him home connected the new Athenian leadership at sea with the city’s legendary past. Plutarch says the Athenians welcomed the relics with processions and sacrifices, as if Theseus himself had come back. Whether the bones were really his, no one can say; the ancient writers report what the Athenians believed.

FACT A hero’s homecoming. Plutarch says Cimon found the grave because an eagle was seen pecking at a mound and scratching the earth with its talons. Inside lay a large coffin, a bronze spearhead and a sword (Plutarch, Life of Theseus and Life of Cimon). It is a story from 600 years later, told about a man the Athenians honoured.

Naxos: the first ally kept in by force

Around 470 BC the large island of Naxos, one of the original members, decided to leave the League. The Athenians and their allies besieged it and forced it back in. For Thucydides this was a turning point: it was “the first instance of the engagement being broken by the subjugation of an allied city, a precedent which was followed by that of the rest in the order which circumstances prescribed”.16 Thucydides gives no date; modern reconstructions put the revolt between about 471 and 467 BC.

Thucydides explains why such revolts happened, and why they failed. The commonest causes were unpaid tribute, ships not delivered and men refusing to serve, because the Athenians were strict and demanding with allies who were not used to constant campaigning. And the allies had partly themselves to blame: to avoid serving away from home, most of them chose to pay money instead of supplying ships, so that Athens built up its own navy with their money, while they had neither the ships nor the experience to resist when they wanted to leave.17

Plutarch tells the same story from the other side, as a deliberate policy of Cimon. Instead of punishing allies who would not serve, Cimon accepted money and empty ships from them and let them stay at home, while he kept large numbers of Athenians at sea and trained them in constant campaigns. In the end, Plutarch writes, the allies “found themselves after a while allies no longer, but unwittingly become tributaries and slaves”.18

Untangled History · ships or money?

Gave ships and crewsAt first: many of the larger allies, which kept their own fleets and fought beside the Athenians.By 431 BC: only Chios and Lesbos (Thucydides 1.19, 2.9).They kept their own navies, and with them some independence.

Paid money insteadAt first: smaller cities, for which a trireme was too expensive.By 431 BC: “all except Chios and Lesbos”.Their money built Athenian ships; a city without ships could not leave.

Thucydides 1.96, 1.99, 1.19 and 2.9; Plutarch, Life of Cimon. No complete list survives for the early years.

From alliance to empire

Thucydides, who lived through the war that this empire caused, describes the change without sentiment. Athens took over the leadership with the allies’ consent, then gradually turned the alliance into a source of power: “Athens, on the contrary, had by degrees deprived hers of their ships, and imposed instead contributions in money on all except Chios and Lesbos.”19 By 431 BC, he says, Athens drew an average of 600 talents a year from the tribute of the allies.20 Plutarch adds that the total was later doubled and then trebled.21

The clearest sign of the change came in 454 BC, when the treasury was moved from Delos to Athens. From that year the Athenians inscribed on stone the sixtieth part of each city’s tribute that was dedicated to Athena, and the fragments of these “tribute lists”, found on the Acropolis, are the most important documents of the League that survive.22 Plutarch reports a revealing remark attributed to Aristides himself: when the Samians proposed moving the money to Athens, he said that it was not just, but it was expedient.23 Whether the story is true is uncertain; Aristides probably died before 454 BC.

Marble slab inscribed with columns of Greek city names and sums of money from the Athenian tribute lists — Part of the Athenian tribute lists, recording the share of each city’s tribute given to Athena, 439–432 BC (Epigraphic Museum, Athens). Photo: NA (Wikimedia user), CC BY 2.5, Wikimedia Commons.

WORD Hellenotamiai. The “Treasurers for Hellas”, the board of Athenian officials who received and managed the League’s money. The name presented the money as belonging to all the Greeks, even though only Athenians held the office (Thucydides 1.96).

The end of Pausanias

Pausanias did not accept his removal. He returned to Byzantium on his own account in a ship from Hermione, was driven out by the Athenians, and settled for a time at Colonae in the Troad, where he was said to be intriguing with the Persians. Recalled to Sparta a second time, he was imprisoned and released, but suspicion grew: he was said to have promised the helots freedom and citizenship if they would rise with him.

The proof, Thucydides says, came from his own messenger, a man from Argilus, who noticed that none of the earlier messengers to the Persian governor had come back. He opened the letter he was carrying and found an order to have him killed. He took the letter to the ephors and went as a suppliant to Taenarus, where he hid some of the ephors behind a partition in his hut so that they heard Pausanias admit everything. When the ephors came to arrest him in the street, Pausanias fled into the temple of Athena of the Brazen House. The ephors took off the roof of the room where he had taken refuge, walled him in and starved him; they carried him out just before he died, so as not to pollute the temple. Diodorus adds that Pausanias’ own mother placed the first brick in the doorway.24

The victor of Plataea thus died as a traitor, probably around 470 BC; Thucydides gives no year. How much of the story is true cannot be checked. The letters Thucydides quotes may come from Spartan accounts written after the event, and the Spartan authorities had their own reasons to blacken a man who had become too powerful. What is certain is that his fall ended Sparta’s leadership at sea for a generation.

Themistocles flees to Persia

The investigation of Pausanias also brought down Themistocles, the victor of Salamis. He had already been ostracised, sent into exile for ten years by a vote of the Athenian assembly, and was living at Argos. Plutarch explains ostracism as a way to humble men who had become too powerful for a democracy. When the Spartans claimed that evidence against Pausanias also implicated Themistocles, Athens and Sparta sent men to arrest him.

His escape reads like an adventure story. He fled to Corcyra, then to the court of Admetus, king of the Molossians, who was no friend of his; on the advice of the king’s wife he sat at the hearth holding their child, as a suppliant, and Admetus refused to hand him over. He crossed Macedonia and boarded a merchant ship for Ionia; a storm drove it towards the Athenian fleet that was besieging Naxos, and Themistocles, unknown to the passengers, told the captain who he was and threatened to accuse him of taking a bribe unless he kept everyone on board until they could sail on. He landed at Ephesus and wrote to the new Persian king, Artaxerxes, son of Xerxes: “I, Themistocles, am come to you, who did your house more harm than any of the Hellenes.”25

He asked for a year’s grace, spent it learning the Persian language and customs, and then came to the court, where, Thucydides says, he reached a standing “such as no Hellene has ever possessed before or since”. The king gave him the revenues of three cities in Asia Minor: Magnesia, worth fifty talents a year, for his bread, Lampsacus for his wine and Myus for his other provisions. He died at Magnesia, of disease according to Thucydides, although there was also a story that he poisoned himself rather than lead a Persian army against Greece.

Untangled History · three versions of Themistocles in Persia

Thucydidesc. 400 BC · within living memoryDiodorusc. 30 BC · four centuries laterPlutarchc. AD 100 · nearly six centuries laterWHICH KINGArtaxerxes, son of Xerxes, newly on the throneXerxes himselfReports both; says Thucydides and Charon of Lampsacus fit the chronology betterTHE PERSIAN LANGUAGELearned in a year’s grace before meeting the kingLearned while waiting for a trial at courtLearned in a year (Life of Themistocles)THE GIFTSMagnesia for bread, Lampsacus for wine, Myus for other foodThe same three cities, and a Persian wife (probably invented, says his translator)The same three; some writers add two moreHIS DEATHDisease; a story of poisonNot described hereBull’s blood or poison, at Magnesia, aged 65

Thucydides 1.135–138; Diodorus 11.54–58; Plutarch, Life of Themistocles. Colours show how far each writer was from the events.

The later writers tell the story differently. Diodorus has Themistocles come to Xerxes himself, learn Persian while waiting for a trial, and receive a Persian wife along with the three cities; his translator notes that the wife is attested only by Diodorus and is almost certainly fictitious.26 Plutarch knew both versions and noted that Thucydides and Charon of Lampsacus, an early historian, said Xerxes was already dead, which the chronology supports. He also preferred the dramatic ending: Themistocles drank bull’s blood, “as is the usual story”, or poison.27

The Persian perspective

A lost coastline, and Greeks for hire

For the Persian kings the years after 479 BC brought losses on the western edge of the empire, but no threat to its heart. The Greek cities of the islands and the coast fell away, Persian garrisons were driven out of Thrace and the Hellespont, and the satrapies of Asia Minor now faced a hostile fleet. Yet the interior of Anatolia and the rich provinces beyond remained Persian, and Persian governors still ruled from Sardis and Dascylium.

Persia’s answer was money and diplomacy as much as war. Xerxes, Thucydides says, sent Artabazus, “son of Pharnaces, to the sea with orders to supersede Megabates, the previous governor in the satrapy of Daskylion”, to deal with Pausanias.28 Within a few years the two most famous Greek commanders of the war had been accused of working for Persia, and one of them, Themistocles, ended his life as a Persian governor in Asia Minor. A Greek exile at the king’s court was nothing new: the deposed Spartan king Demaratus had come up to Susa in the time of Darius and marched with Xerxes in 480 BC.29

No Persian text describes these events. The Persian side reaches us only through Greek writers, and above all through Thucydides, who saw the empire mainly as the source of gold and intrigue in Greek politics. Persia also kept the strength to build a new fleet and army in the east, which Cimon would meet at the river Eurymedon around 466 BC.

How close is our evidence?

Untangled History · how close is our evidence?

480 BCAD 100

Tribute lists (inscriptions)from 454 BC · written at the time

Herodotus, end of book 9c. 430 BC · Sestos only

Thucydides, book 1c. 400 BC · within living memory

Diodorusc. 30 BC · 450 years later

Plutarch, Aristides, Cimon, Themistoclesc. AD 100 · nearly 600 years later

Pausaniasc. AD 160 · Theseus’ bones

Written at the timeWithin living memoryCenturies later

For the founding of the League and its first twenty years we depend almost entirely on Thucydides, who wrote a short sketch of the period in book 1 of his history to explain how Athens became powerful enough to frighten Sparta. He gives the order of events but very few dates, and he wrote with the later empire in mind. The tribute lists on stone begin only in 454 BC. Diodorus and Plutarch add colourful stories, such as the iron in the sea, the eagle on Scyros and Themistocles’ death, but they wrote centuries later and often disagree with each other and with Thucydides.

Why the Delian League mattered

The Delian League achieved what it was founded for. Within a generation the Persian garrisons were gone from Europe, the Aegean was an Athenian sea, and around 466 BC Cimon would destroy a Persian fleet far to the east at the Eurymedon. No Persian fleet of the old size would sail into the Aegean again for decades.

But the League also changed the Greek world in ways its founders had not intended. A voluntary alliance of free cities became an empire, in which most cities paid money to Athens and could not leave. That money paid for the Athenian fleet, for the democracy that depended on the rowers who manned it, and later for the buildings on the Acropolis. And it made Athens powerful enough to alarm Sparta. Thucydides wrote his account of these years for exactly that reason: to explain how the growth of Athenian power led to the great war between Athens and Sparta that began in 431 BC.

Silver Athenian tetradrachm showing the owl of Athena, an olive sprig and the letters ATHE — An Athenian silver “owl”, the coin of the League’s leading city, 5th century BC. Photo: cgb.fr, CC BY 4.0, Wikimedia Commons.

Sources

Thucydides, History of the Peloponnesian War 1.19, 1.89–1.101, 1.128–1.138 and 2.13 (the League, Pausanias, Themistocles). Translation by R. Crawley.

Herodotus, Histories 7.3, 7.101, 8.121, 9.106 and 9.114–121 (Demaratus, Carystus, Samos and Sestos). Translation by A. D. Godley.

Diodorus Siculus, Library of History 11.44–11.47, 11.54–11.60. Translation and notes by C. H. Oldfather (1946).

Plutarch, Lives of Aristides, Cimon and Themistocles (written c. AD 100). Translation by J. Dryden and A. H. Clough.

Pausanias, Description of Greece 3.3.7. Translation by A. R. Shilleto.

Modern studies: R. Meiggs, The Athenian Empire (1972); P. J. Rhodes, The Athenian Empire (1985); A. French, Antichthon 22 (1988); J. Roisman and J. C. Yardley (2011); G. Grote (1847), dated.

Map and dates: the map is schematic; dates after 478 BC are approximate modern reconstructions.

Notes

General sources

Herodotus, Histories: 8.121, 9.106, 9.116, 9.118, 9.120, 9.121
Thucydides, History of the Peloponnesian War: 1.94, 1.95, 1.96, 1.98, 1.130, 1.132, 1.134, 1.135, 1.136, 1.137, 1.138
Grote, History of Greece, vol. 5: ch. 44
Plutarch, Aristides
Plutarch, Cimon
Diodorus Siculus, Library of History: 11.57, 11.60
Plutarch, Themistocles