Delian League (478 BC): From Greek Alliance to Athenian Empire

The Delian League was an alliance of Greek city-states founded in the winter of 478/477 BC on the island of Delos to continue the war against Persia under Athenian leadership. Over the following decades Athens turned this voluntary alliance into an empire, using its members’ payments to build a dominant navy and to fund projects at home. The league lasted until Athens’ defeat in 404 BC.

Background

In 479 BC the Greeks defeated the Persians on land at the Battle of Plataea and on the Ionian coast at Mycale. Persia still ruled much of the eastern Aegean and could return. The newly freed Greeks of Ionia and the islands wanted an alliance that would protect them and take revenge for the destruction of Greek temples.

The obvious leader was Sparta, which had commanded the Greek forces in 480–479 BC. In 478 BC the Spartan regent Pausanias led an allied fleet to Cyprus and then captured Byzantium. His high-handed and allegedly Persian-style behaviour offended the allies, who asked the Athenians to take command. Sparta recalled Pausanias and sent a replacement, but the allies refused to accept him, and Sparta withdrew from naval leadership.

Founding on Delos

The new alliance met at Delos, a small island sacred to Apollo in the centre of the Cyclades, long a religious meeting place for the Ionian Greeks. Its treasury was kept in the temple there. According to Aristotle and Plutarch, the members swore their oaths by dropping lumps of iron into the sea, meaning the alliance would last until the iron rose again.

The Athenian statesman Aristides, known as “the Just”, assessed what each member should contribute. Larger states supplied ships and crews; others paid money, called phoros (tribute). Thucydides puts the first total at 460 talents a year, a very large sum. Ten Athenian officials, the hellenotamiai or “treasurers of the Greeks”, collected and managed it.

Members swore to have the same friends and enemies. In principle the allies met in a common council on Delos, where each state had one vote, but in practice Athens dominated from the start.

From alliance to empire

Under the Athenian general Cimon, son of Miltiades, the league had real military success. It captured Eion on the river Strymon from its Persian garrison around 476 BC, took the island of Skyros, and around 466 BC won a double victory on land and sea at the Eurymedon river in southern Anatolia, destroying a Persian fleet.

As the Persian danger faded, some members wanted to leave. Naxos tried to withdraw around 470 BC and was besieged and forced back in; Thucydides calls it the first allied city to be “enslaved” contrary to established practice. Thasos revolted in 465 BC over a dispute about mines and trading posts and surrendered in 463 BC, losing its walls and fleet.

More and more members chose to pay money rather than send ships. This suited both sides in the short term, but it meant that Athens alone owned and manned the fleet, and the allies lost the means to resist. In 454 BC, probably after a disastrous Athenian expedition to Egypt, the treasury was moved from Delos to Athens. From then on one-sixtieth of each year’s payments was given to Athena, and the records of these offerings, carved on stone, survive as the Athenian Tribute Lists.

Athens increasingly treated the allies as subjects. It required many legal cases to be heard in Athenian courts, planted Athenian settlers (cleruchies) on allied land, and by a decree of uncertain date ordered the use of Athenian coins, weights and measures. Fighting with Persia appears to have ended around 449 BC; whether a formal Peace of Callias was ever signed is still debated, but the tribute continued.

Key people

• Aristides: Athenian statesman who negotiated the alliance and fixed the first tribute assessment.
• Cimon: Leading Athenian general of the 470s and 460s, victor at the Eurymedon.
• Pericles: Dominant Athenian politician from the 450s, who defended the use of league money for Athens’ building programme, including the Parthenon.
• Pausanias: Spartan regent whose conduct in 478 BC drove the allies to Athens.

The end of the league

Fear of Athenian power was, in Thucydides’ view, the deepest cause of the Peloponnesian War, which broke out in 431 BC. During the war Athens raised the tribute steeply in 425 BC and dealt harshly with revolts such as Mytilene (427 BC) and with the neutral island of Melos (416 BC). In 413 BC it replaced the tribute with a 5 per cent tax on seaborne trade.

After the destruction of its fleet at Aegospotami in 405 BC, Athens was besieged and surrendered in 404 BC. It lost its navy and its subject allies, and the league ceased to exist. A Second Athenian League, founded in 378 BC, was deliberately designed to avoid the abuses of the first.

By the numbers

How the empire was experienced

Historians still debate how much the allies resented Athenian rule. Thucydides, an Athenian himself, presents the empire as a tyranny held by force, and has Athenian speakers admit as much. The revolts of Naxos, Thasos, Samos (440–439 BC), Mytilene and, after 413 BC, many Ionian cities support this view.

Others point out that the tribute lists show most members paying regularly for decades, and that Athens often supported democratic factions in allied cities against local oligarchs. For ordinary citizens in many member states, Athenian protection meant safe seas, open trade and a friendly democratic government. Resentment seems to have been strongest among the wealthy elites who lost power and paid most of the costs.

The term “Delian League” itself is modern. Ancient writers usually spoke of “the Athenians and their allies”, a phrase that already hints at who was in charge. Some Athenian decrees of the period speak plainly of the cities that the Athenians control.

The empire also changed Athens. Tribute and the business it generated paid the wages of thousands of rowers, many of them poor citizens, and helped make full democracy affordable. Athenian courts, harbour duties and the market of Piraeus all profited from the allies, so that support for the empire ran deep among ordinary Athenians.

Timeline

• 479 BC, August: Greek victories at Plataea and Mycale.
• 478 BC: Pausanias captures Byzantium; the allies turn to Athens.
• 478/477 BC, winter: Founding of the league on Delos; Aristides assesses the tribute.
• c. 470 BC: Naxos tries to leave and is forced back in.
• c. 466 BC: Cimon defeats the Persians at the Eurymedon.
• 465–463 BC: Revolt and surrender of Thasos.
• 454 BC: Treasury moved from Delos to Athens.
• 431 BC: Outbreak of the Peloponnesian War.
• 404 BC, spring: Athens surrenders; the league is dissolved.

Why it matters

The Delian League shows how a defensive alliance among equals can turn into domination by its strongest member. Its money paid for the Athenian navy, for the democracy that depended on paid rowers and jurors, and for the monuments of the Acropolis. The resentment it created among allies and rivals helped bring about the war that ended Athens’ golden age.