Not long after their return from Euboea, they made a truce with the Lacedaemonians and their allies for thirty years, giving up the posts which they occupied in Peloponnese, Nisaea Pegae, Troezen, and Achaia.

In the sixth year of the truce, war broke out between the Samians and Milesians about Priene. Worsted in the war, the Milesians came to Athens with loud complaints against the Samians. In this they were joined by certain private persons from Samos itself, who wished to revolutionize the government.

Accordingly the Athenians sailed to Samos with forty ships and set up a democracy; took hostages from the Samians, fifty boys and as many men, lodged them in Lemnos, and after leaving a garrison in the island returned home.

But some of the Samians had not remained in the island, but had fled to the continent. Making an agreement with the most powerful of those in the city, and an alliance with Pissuthnes, son of Hystaspes, the then satrap of Sardis, they got together a force of seven hundred mercenaries, and under cover of night crossed over to Samos.

Their first step was to rise on the commons, most of whom they secured, their next to steal their hostages from Lemnos; after which they revolted, gave up the Athenian garrison left with them and its commanders to Pissuthnes, and instantly prepared for an expedition against Miletus. The Byzantines also revolted with them.

As soon as the Athenians heard the news, they sailed with sixty ships against Samos. Sixteen of these went to Caria to look out for the Phoenician fleet, and to Chios and Lesbos carrying round orders for reinforcements, and so never engaged; but forty-four ships under the command of Pericles with nine colleagues gave battle, off the island of Tragia, to seventy Samian vessels, of which twenty were transports, as they were sailing from Miletus. Victory remained with the Athenians.