became one of the most formidable foes which the allied Greek had to
meet.

28. The negotiations continued through the spring, but as summer
approached the army of Mardonius was on the move. Sparta was not ready
to meet the invader, and the Athenians once more took refuge on their
ships, ten months after their return. Mardonius took possession of the
city, and this time effectually destroyed it; but as nothing was to be
gained by a further stay, he marched his army to Thebes, which became
his headquarters. The Spartans were at length ready to march. They saw
their city menaced, and their own safety demanded that the forces of
Mardonius should be broken.

29. With the aid of their allies they put into the field an army, the
largest that the Greeks ever mustered, variously reported as numbering
one hundred thousand to one hundred and ten thousand men. These were
under the command of the Spartan king, Pausanias. In September they
set out for Thebes, and in a few days came up to the Persian army,
which was stationed at Plataea, a short distance from Thebes. Here
Mardonius had established a fortified camp to which he might retreat
if defeated on the field. For eleven days the two armies confronted
each other, neither anxious to strike the first blow. Then the supply
of water for the Greek camp gave out, and Pausanias fell back to a
better position.

30. This movement threw the Greek army into disorder, and the three
main divisions became separated from one another. Perceiving this the
next morning, Mardonius hastened with his Persians toward the higher
ground, where the Spartan troops might be seen winding along under the
hillside, for from the river-banks he could not catch sight of the