The Twitter Herodotus

9.21 The Megarians were especially hard pressed by the cavalry. 300 Athenians volunteered to help them. They were commanded by Olympiodorus.

9.22 There was another battle during which Masistius was killed. When the Persians realized he was dead they attacked to recover the corpse.

9.23 The 300, being worsted by the cavalry, summoned reinforcements. Together they beat the Persians, who withdrew w/o retrieving the body.

9.24 The Persians mourned Masistius, shaving their heads and their horses' manes and their other animals. Their lamentations filled Boeotia.

9.25 Meanwhile, the Greeks paraded Masistius' corpse around on a wagon. They then moved their camp to a place where there was more water.

9.26 The Tegeans and Athenians fought over who would hold the army's left wing. (The Spartans were on the right.) The Tegeans spoke first.

9.27 The Athenians argued for the left wing next, citing inter alia their victory over the Persians at Marathon. The Athenians won the day.

9.28 The Greeks took up their positions: the Spartans on the right, Athenians on the left & all the other Greeks by divisions in the middle.

9.29 There were 38,700 hoplites gathered at Plataea and 69,500 lightly armed troops. 

9.30 There were also 1800 Thespians present, though they had no armor. All together, then, the Greeks had 110,000 at Plataea.