=139.= The Thasians, meanwhile, had a contest with Athens for some gold mines in Thrace. Cimon conducted a fleet to Thasos, gained a naval victory, and began a three years’ siege of the principal town. The Thasians sent to Sparta for help, and that state was preparing to render it with great alacrity, when her attention was suddenly absorbed at home by unforeseen calamities. An earthquake of unprecedented violence first destroyed the city. Great rocks from Mount Taygetus rolled into the streets, and multitudes of persons were engulfed or buried beneath the ruins of their houses. The shocks were long-continued, and terror of the supposed wrath of Heaven was added to the anguish of poverty and bereavement. The dreaded vengeance soon appeared in human form; for the persecuted Helots, hearing the signal of their deliverance in the stroke of doom to Sparta, flocked together from the fields and villages, and mingled their revenge with the commotions of Nature. It was a terrible moment for Sparta; but her king, Archidamus, was true to the stern valor of his race. The shocks of the earthquake had hardly ceased, when he ordered the trumpets to sound to arms. Even at that fearful moment Spartan discipline prevailed. Every man who survived hastened to the king, and when the disorderly, servile crowd approached, they found a disciplined force ready to resist them. Sparta was saved for the moment; the insurgents fled and scattered themselves over the country, calling to their standard all who were oppressed. The Messenians rose in a mass, seized Ithome, where their never-forgotten hero, Aristomenes, had so long withstood the Lacedæmonian arms, fortified it anew, and formally declared war against Sparta. The ten years’ conflict which followed is known as the Third Messenian War (B. C. 464-455). In her extremity, Sparta sent to Athens for aid, and the appeal produced a violent controversy between the two parties into which that city was divided. Cimon favored the Spartans; he had always held up their brave and hardy character as a model to his countrymen, and had even sacrificed much of his popularity by naming his son Lacedæmonius. When others urged that it was well the pride of Sparta should be humbled, and her power for mischief curtailed, Cimon exhorted his countrymen not to suffer Greece to be maimed by the loss of one of her two great powers, thus depriving Athens of her companion. His generous counsel prevailed, and Cimon led a strong force against the insurgents, who were now driven from the open country and compelled to shut themselves up in the castle of Ithome.