Persia was a kingdom during the time of the ancient Greeks that was located inside what is now known as Iran. The Persians were expert warriors and their leaders were often covetous of lands and riches near and far, that they knew of. The Greeks clashed a number of times with them, most notable when the Spartans led by Leonidas turned back a massive invasion force at Thermopylae, and yes that was a real battle and the "Hot Gates" is a real place, as well as a number of other less well known battles.
