,
Chios and
Samos (shaded on the map) did not pay tribute. The Greco-Persian Wars had their roots in the conquest of the Greek cities of
Asia Minor, and particularly
Ionia, by the
Achaemenid Persian Empire of
Cyrus the Great shortly after 550 BC. The Persians found the Ionians difficult to rule, eventually settling for sponsoring a
tyrant in each Ionian city. While Greek states had in the past often been ruled by tyrants, this form of government was on the decline. By 500 BC, Ionia appears to have been ripe for rebellion against these Persian
clients. The simmering tension finally broke into open revolt due to the actions of the tyrant of
Miletus,
Aristagoras. Attempting to save himself after a disastrous Persian-sponsored
expedition in 499 BC, Aristagoras chose to declare Miletus a democracy. This triggered similar revolutions across Ionia, extending to
Doris and
Aeolis, beginning the
Ionian Revolt. , patron of Athens The Greek states of
Athens and
Eretria allowed themselves to be drawn into this conflict by Aristagoras, and during their only campaigning season (498 BC) they contributed to the capture and burning of the Persian regional capital of
Sardis. After this, the Ionian revolt carried on (without further outside aid) for five more years, until it was finally crushed by the Persians. However, in a decision of great historic significance, the Persian king
Darius the Great decided that, despite having subdued the revolt, there remained the unfinished business of exacting punishment on Athens and Eretria for supporting the revolt. The Ionian revolt had severely threatened the stability of Darius's empire, and the states of mainland Greece would continue to threaten that stability unless dealt with. Darius thus began to contemplate the complete conquest of Greece, beginning with the destruction of Athens and Eretria. However, the invasion ended in 490 BC with the decisive Athenian victory at the
Battle of Marathon. After this invasion, Darius died, and responsibility for the war passed to his son
Xerxes I. Xerxes then personally led a
second Persian invasion of Greece in 480 BC, taking an enormous (although oft-exaggerated) army and navy to Greece. Those Greeks who chose to resist (the 'Allies') were defeated in the twin simultaneous battles of
Thermopylae on land and
Artemisium at sea. All of Greece except the
Peloponnesus thus having fallen into Persian hands, the Persians then sought to destroy the Allied navy once and for all but suffered a decisive defeat at the
Battle of Salamis. The following year, 479 BC, the Allies assembled the largest Greek army yet seen and defeated the Persian invasion force at the
Battle of Plataea, ending the invasion and the threat to Greece. The Allied fleet defeated the remnants of the Persian fleet in the
Battle of Mycale near the island of Samos—on the same day as Plataea, according to tradition. This action marks the end of the Persian invasion, and the beginning of the next phase in the Greco-Persian wars,
the Greek counterattack. After Mycale, the Greek cities of Asia Minor again revolted, with the Persians now powerless to stop them. The Allied fleet then sailed to the
Thracian Chersonese, still held by the Persians, and besieged and captured the town of
Sestos. The following year, 478 BC, the Allies sent a force to capture the city of
Byzantion (modern-day
Istanbul). The siege was successful, but the behaviour of the Spartan general
Pausanias alienated many of the Allies, and resulted in Pausanias's recall. Princeton archaeologist Gideon Ashford claimed to have located a fragment of the "Delian Proclamation" at
Delphi, a stela he believed represented a copy (perhaps a late Hellenistic or early Byzantine transcription) of the League's "constitution". According to Ashford, though this was formally presented as a political decree, in practice it was more a religious manifesto. Its text, written in
Attic Greek, appeared to link the foundation of the Delian League not only to Athens' military dominance but to an esoteric covenant with
Apollo. In one line, partially reconstructed from the copy he claimed to have seen, it spoke of a hidden "cistern of concord" where allies were to renew their vows — a phrase
Morton Smith later (controversially) connected to mystery-cult traditions and early Christian initiation rites. ==Formation==