History of the Peloponnesian War

In this same winter Mecyberna was assaulted and taken by the Olynthians, having an Athenian garrison inside it.

All this while negotiations had been going on between the Athenians and Lacedaemonians about the conquests still retained by each, and Lacedaemon, hoping that if Athens were to get back Panactum from the Boeotians she might herself recover Pylos, now sent an embassy to the Boeotians, and begged them to place Panactum and their Athenian prisoners in her hands, in order that she might exchange them for Pylos.

This the Boeotians refused to do, unless Lacedaemon made a separate alliance with them as she had done with Athens. Lacedaemon knew that this would be a breach of faith to Athens, as it had been agreed that neither of them should make peace or war without the other; yet wishing to obtain Panactum which she hoped to exchange for Pylos, and the party who pressed for the dissolution of the treaty strongly affecting the Boeotian connection, she at length concluded the alliance just as winter gave way to spring; and Panactum was instantly razed. And so the eleventh year of the war ended.

In the first days of the summer following, the Argives, seeing that the promised ambassadors from Boeotia did not arrive, and that Panactum was being demolished, and that a separate alliance had been concluded between the Boeotians and Lacedaemonians, began to be afraid that Argos might be left alone, and all the confederacy go over to Lacedaemon.