There can be little doubt that Pericles, who was mainly responsible
for this decision, committed a fatal error in advising the Athenians
to take up the cause of Corcyra. By this act Athens incurred the
implacable hostility of Corinth, and revived the old grudge which that
city had conceived against her when Megara joined the Athenian
alliance. In the constantly shifting currents of Greek politics,
Athens might well, under wise guidance, have steered her way safely
through the perils which surrounded her. The Corinthians had half
forgotten their grievance, as is proved by their conduct at the revolt
of Samos; and the tone of their representative at the Corcyraean
debate is decidedly friendly. The Spartans were sluggish and
procrastinating by nature, and required some powerful impulse to
induce them to act with vigour; and this impulse was now supplied by
Corinth. By accepting, therefore, the alliance of Corcyra, Athens
barred the way to all compromise, and gathered into one head all the
scattered causes of jealousy and hatred which had been accumulating
against her in the last fifty years.

Early in the following year the Corinthian fleet, numbering a hundred
and fifty sail, put to sea from Corinth, to renew the war with
Corcyra, and a battle was fought off the coast of Epirus. The
engagement was long and fierce, and the event was finally decided by a
small squadron of Athenian ships, which had been sent with
instructions to hinder any attempt of the enemy to land on the island
Seeing that the Corcyraeans were being forced back upon their own
coast, the Athenian captains, who had hitherto looked on, and taken no
part in the battle, now assumed the offensive, and lent such effectual
aid that the Corinthians were held in check until the sudden
appearance of twenty additional ships from Athens, which had been sent