of Samos and Chios. The cities of Ionia had remained independent until they were conquered by the famous Lydian king Croesus, in around 560 BC. The Ionian cities then remained under Lydian rule until Lydia was in turn conquered by the nascent Achaemenid Empire of Cyrus the Great. The Persians found the Ionians difficult to rule. Elsewhere in the empire, Cyrus was able to identify elite native groups to help him rule his new subjects—such as the priesthood of Judea. No such group existed in Greek cities at this time; while there was usually an aristocracy, this was inevitably divided into feuding factions. The Persians thus settled for the sponsoring a tyrant in each Ionian city, even though this drew them into the Ionians' internal conflicts. Furthermore, a tyrant might develop an independent streak, and have to be replaced. The tyrants themselves faced a difficult task; they had to deflect the worst of their fellow citizens' hatred, while staying in the favour of the Persians. About 40 years after the Persian conquest of Ionia, and in the reign of the fourth Persian king, Darius the Great, the stand-in Milesian tyrant Aristagoras found himself in this familiar predicament. Aristagoras's uncle Histiaeus had accompanied Darius on campaign in 513 BC, and when offered a reward, had asked for part of the conquered Thracian territory. Although this was granted, Histiaeus's ambition alarmed Darius's advisors, and Histiaeus was thus further 'rewarded' by being compelled to remain in Susa as Darius's "Royal Table-Companion". Taking over from Histiaeus, Aristagoras was faced with bubbling discontent in Miletus. Indeed, this period in Greek history is remarkable for the social and political upheaval in many Greek cities, particularly the establishment of the first democracy in Athens. The island of Naxos, part of the Cyclades group in the Aegean Sea, was also in this period affected by political turmoil. Naxos had been ruled by the tyrant Lygdamis, a protege of the Athenian tyrant Peisistratos, until around 524 BC, when he was overthrown by the Spartans. After this, a native aristocracy seems to have flourished, and Naxos became one of the most prosperous and powerful of the Aegean islands. Despite its success, Naxos was not immune to class tensions and internal strife, and shortly before 500 BC, the population seized power, expelling the aristocrats and establishing a democracy. In 500 BC, Aristagoras was approached by some of the exiles from Naxos,