[snip] 8. The Battle of Plataia
Mardonios marched with the King’s army up to Thessaly and there he went into winter quarters. The following spring he was joined by 40,000 men under Artabazos who had followed the King in his withdrawal with an original force of 60,000. According to Herodotus the forces of Mardonios were 300,000 infantry plus cavalry; of the infantry, 50,000 had been provided by the Greek allies. This means that Mardonios had under his command the normal full strength of the Persian army, even though the cavalry did not by far come up to the table strength of 50,000 horsemen. But Herodotus states that, at the battle of Plataia that closed the campaign of Mardonios, the cavalry was the part of the Persian army that proved the greatest challenge to the Greeks...
The army of Mardonios, however, was still so strong that the Greeks kept avoiding battle until almost twelve months after Salamis, near the close of the military season, when the Persian army began to give signs of disintegration. The disintegration must have been unavoidable once it became clear that another year had passed without conclusive military or political results. Just before the Greek attack Artabazos, with 40,000 men under his command, deserted Mardonios and began to withdraw from Greece. When the Greeks finally attacked at Plataia the battle turned into butchery; Mardonios himself was not able to escape. [/snip]
https://www.cais-soas.com/CAIS/Military/Persian_wars/persian_wars_plataia.htm
[btw, I think Artabazos was the ancestor of that bald guy who runs Amazon]