assembled to insure the command of the sea.

Against the unlimited resources of the Persian empire and the unity
of plan represented by Xerxes and his generals, the Greeks had
little to offer. They possessed the two advantages of the defensive,
knowledge of the terrain and interior lines,[1] but their resources
were small and their spirit divided. Greece in those days was, as
was later said of Italy, "merely a geographical expression." The
various cities were mutually jealous and hostile, and it took a great
common danger to bring them even into a semblance of cooperation.
Even during this desperate crisis the cities of western Greece,
counting themselves reasonably safe from invasion, declined to
send a ship or a man for the common cause.

[Footnote 1: "'Interior Lines' conveys the meaning that from a
central position one can assemble more rapidly on either of two
opposite fronts than the enemy can, and therefore utilize force
more effectively." NAVAL STRATEGY, A. T. Mahan, p. 32.]

[Illustration: ROUTE OF XERXES' FLEET TO BATTLE OF SALAMIS]

The Persian army advanced without opposition as far as the pass of
Thermopylae, which guarded the only road into the rest of Greece.
Twelve days after the army had started on its march the great fleet
crossed the AEgean to establish contact with the army and bring
supplies. The army was checked by the valor of Leonidas, and the
Persian fleet was intercepted by a Greek fleet which stood guard
over the channel leading to the Gulf of Lamia, thus protecting the
sea flank of Leonidas. The Persian fleet, after crossing the open
sea safely, made its base at Sepias preparatory to the attack on
the Greek fleet. The latter numbered only about 380 vessels to some
1200 of their enemy and the prospects for the Persian cause looked
bright indeed. But as the very number of the Persian ships made it
impossible to beach all of them for the night a large proportion
of them were anchored, lying in eight lines, prows toward the sea.
At dawn a northeast gale fell upon them, and, according to the
Greek accounts, wrecked 400 triremes, together with an uncounted
number of transports. Meanwhile the Greek ships had taken refuge
under the lee of the island of Euboea, and the news of the Persian
disaster was signaled to them by the watchers on the heights.

[Illustration: SCENE OF PRELIMINARY NAVAL OPERATIONS, CAMPAIGN OF
SALAMIS]

As soon as the weather moderated the Greeks returned to their position