An active desire for collaboration between the Greeks in the political field does not manifest itself except starting from the Persian wars. With them begins the history of Greece, understood as the unitary political history of a nation.
The proximity and similar civilization of the Lydians and the Greeks of Asia had facilitated the submission of the Ionians to the Lydians and prepared the civil assimilation of the Lydians to the Ionians. Therefore these early struggles for independence between barbarians and Greeks did not arouse the national sentiment of the Greeks of Asia against the barbarians and had little echo in the motherland. Things changed when the Persian empire replaced the reign of Lydia. It was the largest empire that had ever been, and at the end of the century. VI was in the maximum vigor of its expansion. Far away, very different in civilization and customs, it was not even to think of an assimilation of the Persians to the Greeks. In the Persian the Greek felt the foreign master and he was especially repelled by the immeasurable distance between the monarch and his subjects and the unlimited devotion of the subjects towards the monarch, who in his eyes seemed shameful servitude. For this the Persian rule, although not oppressive, felt like a burden. On the other hand Dario did not intend to stop with the possession of Ionia, but aimed to subdue the Balkan peninsula. The work of submission had to proceed step by step. The northern border of the empire on this side must have been the Danube. The expedition beyond the Danube that Darius himself led into the territory of the Scythians (513 BC) was aimed only at terrifying the Transdanubian tribes and preventing their raids on this side of the river: an aim similar to that which Alexander the Great later proposed with his trans-Danubian expedition, and with his transrenan expeditions Caesar. The end was achieved, although our tradition, by coloring the story of these events in the light of subsequent events, represents the expedition as a failure. After that the conquest of the Balkan peninsula could begin; the island of Thasos subdued, and Aminta, king of Maeedonia, recognized the high sovereignty of the great king. The danger for the still free Greeks was imminent. About 499, taking occasion from internal disputes that broke out in Naxos, the Persians, making use above all of contingents provided by Ionia and in particular by Miletus, attempted the subjugation of that island. The attempt ended in failure. This failure and the incidents between Greek officers and Persian commanders gave the discontent already brewing in Ionia against the foreigner the opportunity to break out into open rebellion. Aristagora, the tyrant of Miletus, took charge of the rebellion, deposing the tyranny and establishing democracy in Miletus and in the other Ionian cities. Inferior on land, the Ionians had maritime superiority over the Persians, which made them almost safe in their fortified cities on the sea. It is understood that the final victory was not possible, given the disparity of forces, without the help of the motherland; but in the peninsula the Greeks, who felt very little solidarity with the brothers of Asia, were not aware of the Persian danger. Thus the Ionians, after a few ships rescued from Athens and Eretria, they were left to themselves. But, animated by that help, they had proceeded victoriously as far as Sardi, setting it on fire (498); what caused the rebellion to spread from the Propontis to the island of Cyprus. The arrival of large Persian forces then prevented the Ionians from holding the open countryside, and Cyprus too was lost. The insurgents therefore had to limit themselves to defending themselves within the walls of their cities. Such a war, with the dangers and sacrifices that it entailed and without any hope of success that would compensate for those sacrifices, made the union between the cities less solid and revived civil disputes. Aristagoras, the shrewd and strenuous leader of the insurrection, had to leave Miletus and perished fighting the Thracians in a colonization attempt at the mouth of the Strimon (496). The Persians now prepared a huge Phoenician squad and concentrated it near Miletus, where it won a victory over the Greeks next to the island of Latle, mainly due to dissensions and defections in the opposing army (494). After that Miletus fell into the power of the Persians and was sacked and devastated, so much so that it never regained its ancient splendor. Ionia was gradually subdued. The victor used mildness in general and tried to pacify souls.