Polymnia   

to be left, exposed as we are in front of all the rest of Greece, to
die in your defence alone and unassisted. If however you do not choose
to send us aid, you cannot force us to resist the enemy; for there
is no force so strong as inability. We shall therefore do our best
to secure our own safety."
Such was the declaration of the Thessalians.
Hereupon the Greeks determined to send a body of foot to
Thessaly by sea, which should defend the pass of Olympus.
Accordingly a force was collected, which passed up the Euripus, and
disembarking at Alus, on the coast of Achaea, left the ships there,
and marched by land into Thessaly. Here they occupied the defile of
Tempe; which leads from Lower Macedonia into Thessaly along the course
of the Peneus, having the range of Olympus on the one hand and Ossa
upon the other. In this place the Greek force that had been collected,
amounting to about 10,000 heavy-armed men, pitched their camp; and
here they were joined by the Thessalian cavalry. The commanders
were, on the part of the Lacedaemonians, Evaenetus, the son of
Carenus, who had been chosen out of the Polemarchs, but did not belong
to the blood royal; and on the part of the Athenians Themistocles, the
son of Neocles. They did not however maintain their station for more
than a few days; since envoys came from Alexander, the son of Amyntas,
the Macedonian, and counselled them to decamp from Tempe, telling them
that if they remained in the pass they would be trodden under foot
by the invading army, whose numbers they recounted, and likewise the
multitude of their ships. So when the envoys thus counselled them, and
the counsel seemed to be good, and the Macedonian who sent it
friendly, they did even as he advised. In my opinion what chiefly
wrought on them was the fear that the Persians might enter by
another pass, whereof they now heard, which led from Upper Macedonia
into Thessaly through the territory of the Perrhaebi, and by the
town of Gonnus- the pass by which soon afterwards the army of Xerxes
actually made its entrance. The Greeks therefore went back to their
ships and sailed away to the Isthmus.
Such were the circumstances of the expedition into Thessaly;
they took place when the king was at Abydos, preparing to pass from
Asia into Europe. The Thessalians, when their allies forsook them,
no longer wavered, but warmly espoused the side of the Medes; and
afterwards, in the course of the war, they were of the very greatest
service to Xerxes.
The Greeks, on their return to the Isthmus, took counsel
together concerning the words of Alexander, and considered where
they should fix the war, and what places they should occupy. The
opinion which prevailed was that they should guard the pass of
Thermopylae; since it was narrower than the Thessalian defile, and
at the same time nearer to them. Of the pathway, by which the Greeks
who fell at Thermopylae were intercepted, they had no knowledge,
until, on their arrival at Thermopylae, it was discovered to them by
the Trachinians. This pass then it was determined that they should
guard, in order to prevent the barbarians from penetrating into Greece
through it; and at the same time it was resolved that the fleet should
proceed to Artemisium, in the region of Histiaeotis, for, as those
places are near to one another, it would be easy for the fleet and
army to hold communication. The two places may be thus described.
Artemisium is where the sea of Thrace contracts into a narrow
channel, running between the isle of Sciathus and the mainland of
Magnesia. When this narrow strait is passed you come to the line of
coast called Artemisium; which is a portion of Euboea, and contains
a temple of Artemis (Diana). As for the entrance into Greece by
Trachis, it is, at its narrowest point, about fifty feet wide. This
however is not the place where the passage is most contracted; for
it is still narrower a little above and a little below Thermopylae. At
Alpini, which is lower down than that place, it is only wide enough
for a single carriage; and up above, at the river Phoenix, near the
town called Anthela, it is the same. West of Thermopylae rises a lofty