In the 6th century BC Chios was in danger to be occupied by the powerful monarchs of Asia. The king of Lydia Aliatis (610 – 560 BC.) rounded on the Ionian cities and began to occupy them. Miletus was the only one to resist. During the long-lasting siege of Miletus, Chios was the only Ionian city willing to help Miletus. We do not know precisely if it sent military help or provided Miletus with food (which is the most likely to have happened). This incident proves the naval force of Chios, which was not afraid of the great military force of the Lydian king. During that period Chios remained free and autonomous and was not subjugated to Lydia.

The situation, however, changed when Persians appeared. Cyrus (559-528 BC.), the founder of the Persian state, after he had invaded and conquered Lydia, whose king was Aliatis’ son, Croesus, he attacked the Ionian cities and began to conquer the one after the other. We do not know precisely if Chios was conquered by Cyrus or Darius. The Persians probably conquered Chios between 518 and 513. At that time Stratis was the tyrant of Chios (the Persians appointed a tyrant as a governor in every city they conquered, so he, in return, informed them about the scheming in the cities and ensured their dominance over the tributary peoples). Chios helped Darius with his expedition against Scythes (513 BC.). During the expedition, the Ionian tyrants constructed a bridge in the Bosporus, in order to help his army pass with safety (700.000 men according to Herodotus). During Darius’ war against Scythes, the tyrants of the Ionian cities wanted to rebel against Darius, after being prompted by the Ionians, who guarded the bridge of the Bosporus. That proposal was not accepted by the tyrants of Miletus, Istiaios, and Chios, Stratis, who believed that if Darius lost his power, they would lose their power, too.