King's Peace (387 BC): Persia Dictates Terms to the Greeks

The King’s Peace, also called the Peace of Antalcidas, was the treaty of 387/386 BC that ended the Corinthian War between Sparta and a coalition of Greek cities. Its terms were issued as an edict of the Persian king Artaxerxes II: the Greek cities of Asia Minor became Persian again, and every other Greek state was declared independent. It marked a low point of Greek freedom from Persian influence, barely a century after the Persian Wars.

Background: the Corinthian War

After winning the Peloponnesian War in 404 BC, Sparta quickly made enemies. Its harsh treatment of former allies alienated Thebes and Corinth, and its campaigns in Asia Minor under King Agesilaus II, launched to protect the Ionian Greeks, brought it into open conflict with Persia. Persian gold, distributed among Sparta’s rivals, helped start the Corinthian War in 395 BC.

The war pitted Sparta against Thebes, Athens, Corinth and Argos. In 394 BC a Persian fleet commanded by the Athenian Conon and the satrap Pharnabazus destroyed the Spartan navy at Cnidus, ending Sparta’s brief naval empire. On land, Sparta won hard-fought battles at Nemea and Coronea in the same year, but the fighting around Corinth turned into a long stalemate.

A change of Persian policy

Athens used the victory at Cnidus to rebuild its Long Walls and regain influence in the Aegean. By the late 390s BC an Athenian revival worried Persia more than Sparta did. Sparta saw its opportunity and sent Antalcidas to negotiate with Tiribazus, the satrap at Sardis.

A first peace conference at Sardis in 392 BC failed, because Athens, Thebes and Argos refused to abandon their gains or allies. Antalcidas persisted. Around 388 BC he travelled with Tiribazus to Susa and won the support of Artaxerxes II himself. Returning with Persian backing, he gathered a fleet of about 80 ships and blockaded the Hellespont in 387 BC, cutting Athens off from its grain supply from the Black Sea. Facing hunger and exhaustion, the coalition gave way.

The terms of the peace

The Greek delegates were summoned to Sardis, where Tiribazus read out the king’s terms, preserved in Xenophon’s Hellenica. In summary:

• The Greek cities in Asia, together with the islands of Clazomenae and Cyprus, belonged to the Persian king.
• All other Greek cities, large and small, were to be autonomous.
• Athens kept the islands of Lemnos, Imbros and Scyros.
• The king would make war, with those who accepted the peace, on anyone who refused it.

The oaths were sworn at Sparta in 386 BC. Thebes at first tried to swear on behalf of all Boeotia, but Agesilaus threatened war, and the Thebans had to accept the independence of the other Boeotian towns.

Sparta as enforcer

The autonomy clause sounded like freedom, but Sparta, as the “champion” of the peace, interpreted it in its own favour. The Boeotian League was dissolved and the political union of Corinth and Argos was broken up. In 385 BC Sparta forced Mantinea in Arcadia to tear down its walls and split into villages. In 382 BC a Spartan commander seized the Cadmea, the citadel of Thebes, in peacetime, and Sparta went on to break up the Chalcidian League around Olynthus.

These actions, carried out in the name of a Persian-backed treaty, caused widespread resentment. Thebes was liberated in 379/378 BC, and in 378/377 BC Athens founded the Second Athenian League, whose charter carefully promised to respect the King’s Peace while uniting states against Spartan aggression.

Consequences

For the Greeks of Ionia, the treaty ended the freedom from Persia they had won in the Persian Wars, which had begun with the failed Ionian Revolt. They remained under Persian rule until Alexander the Great crossed into Asia in 334 BC.

In mainland Greece, the treaty introduced the idea of a “common peace” (koine eirene), a single agreement binding every state. It was renewed in 375 BC and again at a conference in Sparta in 371 BC, when the quarrel over Boeotia led directly to the Battle of Leuctra and the collapse of Spartan power. Persia continued to act as arbiter, with Greek embassies competing for the king’s favour at Susa in the 360s BC.

Key people

• Artaxerxes II (reigned 404–358 BC), the Persian king in whose name the peace was issued. He had earlier defeated his brother Cyrus the Younger, whose Greek mercenaries made the March of the Ten Thousand.
• Antalcidas, the Spartan envoy and admiral who negotiated with Persia and enforced the peace by blockading the Hellespont.
• Tiribazus, satrap of Lydia, who supported Sparta and announced the king’s terms at Sardis.
• Agesilaus II, king of Sparta, who used the treaty to weaken Thebes and dominate Greek affairs.

Timeline

• 395 BC: The Corinthian War begins; the Spartan commander Lysander is killed at Haliartus.
• 394 BC: The Spartan fleet is destroyed at Cnidus; Sparta wins on land at Nemea and Coronea.
• 392 BC: A peace conference at Sardis fails.
• c. 388 BC: Antalcidas and Tiribazus travel to Susa and secure the support of Artaxerxes II.
• 387 BC: Antalcidas blockades the Hellespont; the Greeks hear the king’s terms at Sardis.
• 386 BC: The peace is sworn at Sparta; the Boeotian League is dissolved.
• 382 BC: Spartan troops seize the Cadmea of Thebes.
• 378/377 BC: Athens founds the Second Athenian League.

Why it matters

The King’s Peace showed how divided the Greek city-states had become: a Persian king could settle their wars by decree. It confirmed Persian rule over Ionia for half a century and gave Sparta a licence for heavy-handed domination that soon provoked Theban resistance. Later Greek writers, especially in Athens, remembered it as a shameful betrayal of the Ionian Greeks, a sentiment that Philip II and Alexander the Great would later exploit in their call for war against Persia.