What was the Delian League and what did it do?

The Delian League was an alliance of Greek city-states created as a defence to Persian aggression since each member swore to defend another if attacked. Athens came to dominate the League and use it to raise cash. It is named after the original treasury headquarters on the island of Delos.

Who was in the Delian League?

The Delian League was composed of 330 city-states at its peak. Athens was very much the leader and dominant polis.

Why did the Delian League fail?

The Delian League collapsed because Athens came to dominate it and demand payment from members. Some city-states refused and were attacked by the Athenians, notably Naxos. During the Peloponnesian War, many considered the League as simply being the Athenian Empire and when Athens lost the war to Sparta, so the League was dissolved.

Delian League Timeline

Definition

The Delian League (or Athenian League) was an alliance of Greek city-states led by Athens. The league was formed in 478 BCE to liberate eastern Greek cities from Persian rule. The league was then used as a defence against possible revenge attacks from Persia following the Greek victories at Marathon, Salamis, and Plataea in the early 5th century BCE.

More about: Delian League

Timeline

479 BCE - 478 BCE
Combined Greek operations in the Hellespont and Cyprus.
478 BCE
Samos becomes a member of the Delian League.
478 BCE
Many Cycladic states join the Athenian led Delian League as a defence against Persian agression.
478 BCE - 454 BCE
The treasury of the Delian League is kept on Delos until its removal to Athens.
478 BCE - 404 BCE
The Delian League in Greece, led by Athens.
476 BCE - 463 BCE
Delian League operations are led by Athenian commander Cimon
c. 475 BCE
Athenian general Cimon drives the Dolopian pirates out of the Aegean island of Scyros.
c. 475 BCE
Athenian general Cimon defeats Spartan general Pausanias and takes Byzantium.
475 BCE
Cimon captures Eion in Thrace for Athens.
c. 472 BCE
Carystos forced to join the Delian League.
c. 470 BCE - c. 469 BCE
Attempted secession of Naxos from the Delian League. It is defeated and enslaved.
c. 467 BCE
The island of Naxos rebels against Athenian dominance of the Delian League.
c. 466 BCE
Athenian general Cimon twice defeats the Persians at Eurymedon on the southern coast of Asia Minor.
c. 465 BCE
Secession of Thasos.
465 BCE - 463 BCE
Athenian general Cimon conquers Chersonesus in Thrace and the north-Aegean island of Thasos.
464 BCE - 463 BCE
Earthquake in Sparta, followed by slave revolt. Surrender of Thasos.
462 BCE - 461 BCE
Radicalisation of democracy in Athens; Cimon exiled, Pericles comes to exercise influence.
460 BCE - 459 BCE
Megara switches sides to Athens; outbreak of war with the Peloponnesians & Athenians initially victorious.
c. 457 BCE - 454 BCE
Large expedition to Egypt, to aid rebels against Persian rule.
456 BCE - 455 BCE
Athenians spread their power in northern Peloponnese.
454 BCE
Failure of Egyptian expedition; some Delian League members unsuccessfully revolt. Removal of League treasury from Delos to Athens.
451 BCE - 450 BCE
Peace between Argos and Sparta. Athens and Sparta conclude five-year truce.
450 BCE
Athenian general Cimon dies on Cyprus fighting the Persians.
447 BCE - 446 BCE
Boeotian cities revolt against Athens. Secessions in Euboea and Megara.
446 BCE - 445 BCE
Spartans invade Attica. Thirty Years' Peace between Athens and Sparta.
441 BCE
Revolt of Samos.
436 BCE - 435 BCE
Expedition of Pericles into the Black Sea. Corcyra/Epidamnus affair draws in Corinth and the Athenians.
433 BCE - 432 BCE
Athens concludes treaties with Italiot and Siceliot cities. Megarian decree commercially isolates Megara.
432 BCE
Secession of Potidaea involves Corinthians.
431 BCE - 404 BCE
The 2nd Peloponnesian War between Athens and Sparta (the Delian League and the Peloponnesian League) which involved all of Greece.
428 BCE
Mytilene on Lesbos unsuccessfully revolts against the Athenian domination of the Delian League.
427 BCE
First Athenian expedition to Sicily.
421 BCE
Peace of Nicias, a truce between the Delian and Peloponnesian Leagues.
421 BCE - 416 BCE
"Cold war' between Athens and Corinth.
415 BCE - 413 BCE
Great Athenian expedition to Sicily ends in failure.
413 BCE
Wholesale revolt of Delian League members; War recommences. Spartans and Corinthians gain advantage from League seccessions and help from the Persians.
404 BCE
Athens loses the Peloponnesian War; the Delian League is dissolved.