with seventy vessels. The plot failed owing to the late arrival of the Athenian force, when Nicodromus had already fled the island. An engagement followed in which the Aeginetes were defeated. Subsequently, however, they succeeded in winning a victory over the Athenian fleet. All the incidents subsequent to the appeal of Athens to Sparta are referred expressly by Herodotus to the interval between the sending of the heralds in 491 BC and the invasion of Datis and Artaphernes in 490 BC (cf. Herod. vi. 49 with 94). There are difficulties with this story, of which the following are the principal elements: Herodotus nowhere states or implies that peace was concluded between the two states before 481 BC, nor does he distinguish between different wars during this period. Hence it would follow that the war lasted from soon after 507 BC until the congress at the Isthmus of Corinth in 481 BC It is only for two years (491 and 490 BC) out of the twenty-five that any details are given. It is the more remarkable that no incidents are recorded in the period between the battles of Marathon and Salamis, since at the time of the Isthmian Congress the war was described as the most important one then being waged in Greece, It is improbable that Athens would have sent twenty vessels to the aid of the Ionians in 499 BC if at the time it was at war with Aegina. There is an incidental indication of time, which indicates the period after Marathon as the true date for the events which are referred by Herodotus to the year before Marathon, viz. the thirty years that were to elapse between the dedication of the precinct to Aeacus and the final victory of Athens. As the final victory of Athens over Aegina was in 458 BC, the thirty years of the oracle would carry us back to the year 488 BC as the date of the dedication of the precinct and the beginning of hostilities. This inference is supported by the date of the building of the 200 triremes "for the war against Aegina" on the advice of Themistocles, which is given in the Constitution of Athens as 483–482 BC. It is probable, therefore, that Herodotus is in error both in tracing back the beginning of hostilities to an alliance between Thebes and Aegina () and in claiming the episode of