Herodotus

Herodotus of Halicarnassus here displays his inquiry, so that human achievements may not become forgotten in time, and great and marvellous deeds - some displayed by Greeks, some by barbarians - may not be without their glory; and especially to show why the two peoples fought with each other.
Learned Persians put the responsibility for the quarrel on the Phoenicians. These people came originally from the so-called Red Sea; and as soon as they had penetrated to the Mediterranean and settled in the country where they are today, they took to making long trading voyages. Loaded with Egyptian and Assyrian goods, they called at various places along the coast, including Argos, in those days the most important place in the land now called Greece. 
Here in Argos they displayed their wares, and five or six days later when they were nearly sold out, a number of women came down to the beach to see the fair. Amongst these was the king's daughter, whom Greek and Persian writers agree in calling Io, daughter of Inachus. These women were standing about near the vessel's stern, buying what they fancied, when suddenly the Phoenician sailors passed the word along and made a rush at them. The greater number got away; but Io and some others were caught and bundled aboard the ship, which cleared at once and made off for Egypt.

This, according to the Persian account (the Greeks have a different story), was how Io came to Egypt; and this was the first in a series of unjust acts.

Later on some Greeks, whose name the Persians fail to record -they were probably Cretans -put into the Phoenician port of Tyre and carried off the king's daughter Europa, thus giving them tit for tat. 
For the next outrage it was the Greeks again who were responsible. They sailed in an armed merchantman to Aea in Colchis on the river Phasis, and, not content with the regular business which had brought them there, they abducted the king's daughter Medea. The king sent to Greece demanding reparations and his daughter's return; but the only answer he got was that the Greeks had no intention of offering reparation, having received none themselves for the abduction of Io from Argos.

The accounts go on to say that some forty or fifty years afterwards Paris, the son of Priam, was inspired by these stories to steal a wife for himself out of Greece, being confident that he would not have to pay for the venture any more than the Greeks had done. And that was how he came to carry off Helen.

The first idea of the Greeks after the rape was to send a demand for satisfaction and for Helen's return. The demand was met by a reference to the seizure of Medea and the injustice of expecting satisfaction from people to whom they themselves had refused it, not to mention the fact that they had kept the girl.

Thus far there had been nothing worse than woman-stealing on both sides; but for what happened next the Greeks, they say, were seriously to blame; for it was the Greeks who were, in a military sense, the aggressors. Abducting young women, in their opinion, is not, indeed, a lawful act; but it is stupid after the event to make a fuss about avenging it. The only sensible thing is to take no notice; for it is obvious that no young woman allows herself to be abducted if she does not wish to be. The Asiatics, according to the Persians, took the seizure of the women lightly enough, but not so the Greeks: the Greeks, merely on account of a girl from Sparta, raised a big army, invaded Asia and destroyed the empire of Priam. From that root sprang their belief in the perpetual enmity of the Grecian world towards them - because the Persians claim Asia and the barbarian races dwelling in it as their own, Europe and the Greek states being, in their opinion, quite separate and distinct from them.

Such then is the Persian story. In their view it was the capture of Troy that first made them enemies of the Greeks.
As to Io, the Phoenicians do not accept the Persians' account; they deny that they took her to Egypt by force. On the contrary, the girl while she was still in Argos went to bed with the ship's captain, found herself pregnant, and, ashamed to face her parents, sailed away voluntarily to escape exposure.
So much for what Persians and Phoenicians say; and I have no intention of passing judgment on its truth or falsity. I prefer to rely on my own knowledge, and to point out who it was in actual fact that first injured the Greeks; then I will proceed with my history, telling the story as I go along of small cities of men no less than of great. For most of those which were great once are small today; and those which used to be small were great in my own time. Knowing, therefore, that human prosperity never abides long in the same place, I shall pay attention to both alike.