in the straits near Artemisium, and during the next three days the
two fleets fought stubbornly but without advantage to either side.
During the second day a southerly gale caught a flying squadron
of some 200 triremes, that had been dispatched round the island of
Euboea to catch the Greeks in the rear, and not one of the Persian
ships survived. The Greek rear guard squadron of fifty brought
the welcome news to the main fleet and served as a much needed
reenforcement. Although the Persian armada had lost about half
its force in three days by storms, the odds were still so heavily
against the Greeks that they found themselves in constant peril
of having their flanks turned in this open sea fighting.

On the afternoon of the third day the pass of Thermopyae was forced,
thanks to the treachery of a Greek and the contemptible policy of
the Spartan government which steadily refused the plea of Leonidas
for reenforcements. With Thermopyae taken there was no further reason
for the Greek fleet to try to hold the straits north of Euboea,
and during the night it retired unobserved. The following day the
Persian fleet advanced and brought to the army the supplies which
it sorely needed.

With the fall of Thermopyae and the contact established between his
army and his fleet, Xerxes found his route open for the invasion
of Attica. Since there was no possibility of opposing him on land,
the population of the province was removed and Athens left to its
fate. Themistocles, who was in command of the Athenian division of
the Greek fleet, now urged the assembling of the fleet at Salamis,
partly to cover the withdrawal of the Athenians and partly to assist
in the defense of the Isthmus of Corinth, which was to be the next
stand of the Greeks. The advice was adopted and the fleet assembled
off the town of Salamis. Athenian refugees had crowded into the town
and from the heights above they watched the smoke of their burning
city. Their own future and the future of Athenian civilization hung
on the long lines of triremes drawn up on the shore.

A glance at the map of the region of Salamis shows the advantages
offered by the position for the defensive. The fighting off Artemisium
had shown the peril of attacking a greatly superior force in the open
because of the danger of being outflanked. In the narrow straits
between Salamis and the mainland the Greek line of battle would
rest its flanks on the opposite shores. But it is one thing to