Mardonius had constructed an entrenched camp on the north or left bank of the river Asopus. In front of this camp he drew up his line of battle. The Greek army, which was under the command of Pausanias, uncle of one of the kings of Sparta and regent, took up its position on the slopes of Mount Cithæron. Their unwillingness to descend into the plain and come to close quarters emboldened Mardonius to attack them with his cavalry. The contingent from Megara happened to be in a peculiarly advanced or otherwise exposed situation, and suffered so severely that it had to send for help. It explains Pausanias's apparent timidity when we find that he could not induce any of his troops to go to the assistance of their hard-pressed countrymen. In the end three hundred Athenians volunteered for this service. They took with them a force of archers, an arm in which Megarians were entirely deficient. Some sharp fighting ensued; at last an arrow killed the horse of the Persian general Masistius, and the general, a man of great stature and beauty, and a splendid figure in his gilded chain-armour, was thrown to the ground. This happened close to the Athenian lines, and Masistius was soon killed, though it was only by a thrust in the eye that he could be despatched, so impenetrable was his armour. The Persian cavalry, as soon as it became aware of its leader's fate, charged furiously to recover the body. For a time the Greeks were driven back, but they rallied and recovered the prize. The Persians, demoralised, in the usual fashion of Asiatics, by the loss of their leader, retreated in disorder.