On the return of the Mytilenaean envoys from Athens, where of course they had accomplished nothing, the siege of Mytilene began in earnest. The city was situated on a promontory facing the Asiatic coast on the south-eastern side of the island, and had two harbours, on its northern and southern side. Both of these harbours were now held in close blockade by the Athenians, who established two camps, one on either side of the town, and patrolled the harbour-mouths with their ships. But on the land side the investment was not yet completed, so that supplies could still be brought into the town from the island. Reinforcements, however, came pouring into the Athenian quarters in answer to a summons sent to the cities of the Athenian alliance, who were the more willing to lend help, as the Lesbians made no vigorous effort in their own defence.
While the prospects of Athens were thus brightening, the Mytilenaean envoys, after a stormy voyage, arrived at Sparta, and laid their petition before the authorities. It happened that the Olympic festival was close at hand, where representatives would be present from all the cities of the Peloponnesian league; so the envoys received orders to go to Olympia, and state their case in the presence of the Spartan allies. They went, therefore, to Olympia, and when the festival was over, the Mytilenaean orator addressed the confederates as follows:--
"Before we urge our claim for assistance we wish to combat a prejudice which we know to be general in Greece against those who desert their allies in time of war. For we wish not only to obtain your countenance and support, but also to preserve your respect. To abandon an ally without just cause in a time of peril is justly regarded as an act of treason. But then the alliance must be a fair and equal relation voluntarily assumed on both sides, based on mutual esteem and parity of power. Can anyone assert that our connexion with Athens answers to this description? Have we not seen how the confederacy of maritime cities formed against Persia was gradually converted into an Athenian empire? And though we and the Chians enjoyed nominal independence, we had good reason to fear that this was only a temporary concession, which would be withdrawn as soon as the Athenians felt themselves strong enough to attack us. We were allowed to retain our liberty, partly because they feared our navy, and partly because they wished to make us accomplices in their own aggressions, and lend an appearance of equity to the acts of violence in which we were compelled to take part. Having swallowed up the smaller states, they were ready to pounce upon us, and were only prevented by the outbreak of the present war. Who, then, can blame us, if we seized the opportunity when they were weakened to repudiate this false alliance, and anticipate the blow which they were preparing for us? Athens, we repeat, has no just title to our allegiance; the bond which held us together was fear on our side and interest on theirs. We are natural enemies; and when your foe is disabled, then is the time to strike.