First the Athenians besieged and captured Eion on the Strymon from the Medes, and made slaves of the inhabitants, being under the command of Cimon, son of Miltiades. Next they enslaved Scyros, the island in the Aegean, containing a Dolopian population, and colonized it themselves. This was followed by a war against Carystus, in which the rest of Euboea remained neutral, and which was ended by surrender on conditions. After this Naxos left the confederacy, and a war ensued, and she had to return after a siege; this was the first instance of the engagement being broken by the subjugation of an allied city, a precedent which was followed by that of the rest in the order which circumstances prescribed. Of all the causes of defection, that connected with arrears of tribute and vessels, and with failure of service, was the chief; for the Athenians were very severe and exacting, and made themselves offensive by applying the screw of necessity to men who were not used to and in fact not disposed for any continuous labour. In some other respects the Athenians were not the old popular rulers they had been at first;and if they had more than their fair share of service, it was correspondingly easy for them to reduce any that tried to leave the confederacy. For this the allies had themselves to blame; the wish to get off service making most of them arrange to pay their share of the expense in money instead of in ships, and so to avoid having to leave their homes. Thus while Athens was increasing her navy with the funds which they contributed, a revolt always found them without resources or experience for war.
Next we come to the actions by land and by sea at the river Eurymedon, between the Athenians with their allies, and the Medes, when the Athenians won both battles on the same day under the conduct of Cimon, son of Miltiades, and captured and destroyed the whole Phoenician fleet, consisting of two hundred vessels. Some time afterwards occurred the defection of the Thasians, caused by disagreements about the marts on the opposite coast of Thrace, and about the mine in their possession. Sailing with a fleet to Thasos, the Athenians defeated them at sea and effected a landing on the island. About the same time they sent ten thousand settlers of their own citizens and the allies to settle the place then called Ennea Hodoi or Nine Ways, now Amphipolis. They succeeded in gaining possession of Ennea Hodoi from the Edonians, but on advancing into the interior of Thrace were cut off in Drabescus, a town of the Edonians, by the assembled Thracians, who regarded the settlement of the place Ennea Hodoi as an act of hostility. Meanwhile the Thasians being defeated in the field and suffering siege, appealed to Lacedaemon, and desired her to assist them by an invasion of Attica.
Without informing Athens, she promised and intended to do so, but was prevented by the occurrence of the earthquake, accompanied by the secession of the Helots and the Thuriats and Aethaeans of the Perioeci to Ithome. Most of the Helots were the descendants of the old Messenians that were enslaved in the famous war; and so all of them came to be called Messenians. So the Lacedaemonians being engaged in a war with the rebels in Ithome, the Thasians in the third year of the siege obtained terms from the Athenians by razing their walls, delivering up their ships, and arranging to pay the moneys demanded at once, and tribute in future; giving up their possessions on the continent together with the mine.
The Lacedaemonians, meanwhile, finding the war against the rebels in Ithome likely to last, invoked the aid of their allies, and especially of the Athenians, who came in some force under the command of Cimon.
The reason for this pressing summons lay in their reputed skill in siege operations; a long siege had taught the Lacedaemonians their own deficiency in this art, else they would have taken the place by assault. The first open quarrel between the Lacedaemonians and Athenians arose out of this expedition. The Lacedaemonians, when assault failed to take the place, apprehensive of the enterprising and revolutionary character of the Athenians, and further looking upon them as of alien extraction, began to fear that, if they remained, they might be tempted by the besieged in Ithome to attempt some political changes. They accordingly dismissed them alone of the allies, without declaring their suspicions, but merely saying that they had now no need of them. But the Athenians, aware that their dismissal did not proceed from the more honourable reason of the two, but from suspicions which had been conceived, went away deeply offended, and conscious of having done nothing to merit such treatment from the Lacedaemonians; and the instant that they returned home they broke off the alliance which had been made against the Mede, and allied themselves with Sparta's enemy Argos; each of the contracting parties taking the same oaths and making the same alliance with the Thessalians.
