It would appear that, during the revolt of the helots and Messenians, which lasted ten years, the Athenians, under Cimon, marched twice [181] to the aid of the Spartans. In the first (B. C. 464) they probably drove the scattered insurgents into the city of Ithome; in the second (B. C. 461) they besieged the city. In the interval Thasos surrendered (B. C. 463); the inhabitants were compelled to level their walls, to give up their shipping, to pay the arrear of tribute, to defray the impost punctually in future, and to resign all claims on the continent and the mines. XIV. Thus did the Athenians establish their footing on the Thracian continent, and obtain the possession of the golden mines, which they mistook for wealth. In the second expedition of the Athenians, the long-cherished jealousy between themselves and the Spartans could no longer be smothered. The former were applied to especially from their skill in sieges, and their very science galled perhaps the pride of the martial Spartans. While, as the true art of war was still so little understood, that even the Athenians were unable to carry the town by assault, and compelled to submit to the tedious operations of a blockade, there was ample leisure for those feuds which the uncongenial habits and long rivalry of the nations necessarily produced. Proud of their Dorian name, the Spartans looked on the Ionic race of Athens as aliens. Severe in their oligarchic discipline, they regarded the Athenian Demus as innovators; and, in the valour itself of their allies, they detected a daring and restless energy which, if serviceable now, might easily be rendered dangerous hereafter. They even suspected the Athenians of tampering with the helots--led, it may be, to that distrust by the contrast, which they were likely to misinterpret, between their own severity and the Athenian mildness towards the servile part of their several populations, and also by the existence of a powerful party at Athens, which had opposed the assistance Cimon afforded. With their usual tranquil and wary policy, the Spartan government attempted to conceal their real fears, and simply alleging they had no further need of their assistance, dismissed the Athenians. But that people, constitutionally irritable, perceiving that, despite this hollow pretext, the other allies, including the obnoxious Aeginetans, were retained, received their dismissal as an insult. Thinking justly that they had merited a nobler confidence from the Spartans, they gave way to their first resentment, and disregarding the league existing yet between themselves and Sparta against the Mede--the form of which had survived the spirit--they entered into an alliance with the Argives, hereditary enemies of Sparta, and in that alliance the Aleuads of Thessaly were included.