ited and during this time the Greeks were not idle.
They knew that a final attack was to be expected but they did not agree
upon the best way to avert the danger. Some people wanted to increase
the army. Others said that a strong fleet was necessary for success. The
two parties led by Aristides (for the army) and Themistocles (the leader
of the bigger-navy men) fought each other bitterly and nothing was done
until Aristides was exiled. Then Themistocles had his chance and he
built all the ships he could and turned the Piraeus into a strong naval
base.

In the year 481 B.C. a tremendous Persian army appeared in Thessaly, a
province of northern Greece. In this hour of danger, Sparta, the
great military city of Greece, was elected commander-in-chief. But the
Spartans cared little what happened to northern Greece provided their
own country was not invaded, They neglected to fortify the passes that
led into Greece.

A small detachment of Spartans under Leonidas had been told to guard
the narrow road between the high mountains and the sea which connected
Thessaly with the southern provinces. Leonidas obeyed his orders. He
fought and held the pass with unequalled bravery. But a traitor by the
name of Ephialtes who knew the little byways of Malis guided a regiment
of Persians through the hills and made it possible for them to attack
Leonidas in the rear. Near the Warm Wells--the Thermopylae--a terrible
battle was fought.

When night came Leonidas and his faithful soldiers lay dead under the
corpses of their enemies.

But the pass had been lost and the greater part of Greece fell into the
hands of the Persians. They marched upon Athens, threw the garrison from
the rocks of the Acropolis and burned the city. The people fled to the
Island of Salamis. All seemed lost. But on the 20th of September of the
year 480 Themistocles forced the Persian fleet to give battle within the
narrow straits which separated the Island of Salamis from the mainland
and within a few hours he destroyed three quarters of the Persian ships.

In this way the victory of Thermopylae came to naught. Xerxes was forced
to retire. The next year, so he decreed, would bring a final decision.
He took his troops to Thessaly and there he waited for spring.

But this time the Spartans understood the seriousness of the hour.
They left the safe shelter of the wall which they had built across the
isthmus of Corinth and under the leadership of Pausanias they marched