The Persian forces were established around certain districts, instead of one single force.

They said nothing, simply watched the gathering array of the Persian forces coming from the east.

They furnished a good deal of useful information about the disposition of the Persian forces.

Still, the Persian forces soon withdrew, probably to focus on their invasion of Egypt.

The next morning, shortly after the army resumed its march, a courier arrived from the Persian forces who had gone ahead.

The Persian forces outnumbered them by five to one being some one hundred and fifty thousand strong.

Khalid devised a brilliant plan to destroy the Persian forces.

This led to an invasion of Armenia by the Persian forces.

Herodotus estimated the Persian forces as five million strong, which was obviously exaggerated.

Indeed, most estimates for the total Persian force are generally in this range.