Herodotus Book I, concluded

Herodotus devoted much of the first book to the Persians, their conquest of Lydia, and their subjugation of the Greek cities on the coast of Asia Minor and the offshore islands.  He spends a great deal of time on the Ionian Revolt, provoked by Persian expansion, because it is both the predecessor and a major cause of the first Persian War with the mainland Greek cities. 

The early Greeks, who were not unified either in dialect or ethnicity, were divided into distinct ethnic and dialect groups:  The Ionians, who were predominant in Asia Minor, the Aegean islands, the great island of Euboea, and Athens, represented (with the exception of backward Athens) the cultural elite of the Greek world.  Their dialect, with an admixture of more ancient words from different dialects, was the language of Homer, elegiac poetry, and the philosophers.  The Dorians, a branch of more primitive Northwest Greeks, had taken over the Peloponnesus and spread to Sicily and elsewhere.  The Aeolians believed themselves to be descended from Mycenaean refugees who fled the invading Dorians.  The songs of Sappho and Alcaeus, written in Aeolic Greek, are worth the effort to master the language.  There were, of course, other peoples:  Boetians, who were partly Aeolian, Thessalians, Locrians, et al., but this is only the briefest summary.

In the East, the Ionian and Aeolian Greeks predominated, and, threatened by Persian attacks, they decided to appeal to the most powerful of the mainland cities—Dorian Lacedaemon or Sparta.  The Spartans refused the request for assistance, but in their arrogance sent a deputation to the Persians in Sardis, warning them not to molest any city in Greece [I.152-153].  When Cyrus the Great heard of the threat, he inquired of some Greeks who these people were.  Upon being informed, he replied: “I have never yet been afraid of any men who have a set place in the middle of their city, where they come together to cheat each other and foreswear themselves.”

On the one hand, the noble Persian was justified in suspecting the courage and integrity of mercantile peoples.  Unfortunately, he misjudged the temper not only of the uncommercial Spartans but of most of the Greeks.  Even the Phocaeans, who had taken part in the delegation that went to Sparta, although they were technically Ionian and therefore sophisticated, were among the toughest men of the Mediterranean world.  

When Harpagus, the Persian commander, laid siege to Phocaea, he offered them very generous terms.  He said he would be content if they would tear down one fortified tower and dedicate one house to the Great King.  The Phocaeans would have nothing to do with even token submission, which they regarded as slavery, and asked one day for deliberation.  In that time they packed up everything they could and sailed away [I. 163 ff.] They asked Chios permission to settle some of their islands, but since the Phocaeans were proverbial for piracy, they were told to keep moving.  They went to Alalia on Corsica, where they had planted a settlement.  Before setting out, they made a lightning raid on Phocaea and killed the Persian garrison; however, half the citizens chose to stay.  

The others, after dropping a lump of iron into sea and pledging not to return until the iron rose, went to Corsica, where they raided the shipping of barbarian Carthaginians and Etruscans, who joined forces and attacked the Phocaean fleet.  The Phocaeans won the battle but at great cost.  After deciding to leave, some went to the great colony they had established at Massillia (modern Marseilles); others went to Southern Italy and founded city of Elea.  Both Massallia and Elea prospered, and the latter town became home to one of the greatest philosophers of all time: Parmenides.

The men of Teos took a similar resolution to abandon their city rather than submit to the Persians, but the rest, including the very wealthy Miletus, made the best terms they could, but if the Persians thought they had permanently suppressed the Greek determination to be free—that is, to live in their own cities according to their own customs—he was mistaken.