The immediate circumstances which led to the Ionian Revolt belong to Greek rather than to Persian history, and have been so fully treated of by the historians of the Hellenic race that a knowledge of them may be assumed as already possessed by the reader.  What is chiefly remarkable about them is, that they are so purely private and personal.  A chance quarrel between Aristagoras of Miletus and the Persian Megabates, pecuniary difficulties pressing on the former, and the natural desire of Histiseus, father-in-law of Aristagoras, to revisit his native place, were undoubtedly the direct and immediate causes of what became a great national outbreak.  That there must have been other and wider predisposing causes can scarcely be doubted.  Among them two may be suggested.  The presence of Darius in Asia Minor, and his friendliness towards the tyrants who bore sway in most of the Greek cities, were calculated to elate those persons in their own esteem, and to encourage in them habits and acts injurious or offensive to their subjects.  Their tyranny under these circumstances would become more oppressive and galling.  At the same time the popular mind could not fail to associate together the native despot and the foreign lord, who (it was clear to all) supported and befriended each other.  If the Greeks of Asia, like so many of their brethren in Europe, had grown weary of their tyrants and were desirous of rising against them, they would be compelled to contemplate the chances of a successful resistance to the Persians.  And here there were circumstances in the recent history calculated to inspirit them and give them hopes.  Six hundred Greek ships, manned probably by 120,000 men, had been lately brought together, and had formed a united fleet.  The fate of the Persian land-army had depended on their fidelity.  It is not surprising that a sense of strength should have been developed, and something like a national spirit should have grown up in such a condition of things.

If this were the state of feeling among the Greeks, the merit of Aristagoras would be, that he perceived it, and, regardless of all class prejudices, determined to take advantage of the chance which it gave him of rising superior to his embarrassments.  Throwing himself on the popular feeling, the strength of which he had estimated aright, he by the same act gave freedom to the cities, and plunged his nation into a rebellion against Persia.  It was easy for reason to show, when the matter was calmly debated, that the probabilities of success against the might of Darius were small.  But the arrest of the tyrants by Aristagoras, and his deliverance of them into the hands of their subjects, was an appeal to passion against which reason was powerless.  No state could resist the temptation of getting rid of the tyranny under which it groaned.  But the expulsion of the vassal committed those who took part in it to resist in arms the sovereign lord.