"One of the Trachinians told him [that] such was the number of the barbarians, that when they shot forth their arrows the sun would be darkened by their multitude. Dieneces, not at all frightened at these words, but making light of the Median numbers, answered 'Our Trachinian friend brings us excellent tidings. If the Medes darken the sun, we shall have our fight in the shade.'"
When I read that famous quote by Dieneces, the first thing I thought was: this guy is @#%* crazy! That's probably why when I read Gates of Fire by Steven Pressfield it didn't occur to me until near the end of the book that one of the main characters was the same guy (OK that and the fact the author didn't use the Latin spelling).
While everyone has portrayed Dieneces as a handsome prince or a noble and couragous soldier, my potrayal is totally different. To me, this guy is the slightly-crazed marine that storms the beach screaming, the soldier who obeys orders but has to be kept on a tight leash becauase he's a few cans short of a six pack!
In my mind Dieneces is just short of his middle years. He has thick black cords of hair bound by iron rings that arch down his back. He's muscled, but short and bow-legged and not pretty of face. He sports a necklace of human teeth, a collection from helots he's hunted down and killed over the years. He's a wise ass who loves to push every button of every one of his commanders, save the Agiad king whom he likes and respects. He's not exactly evil but he's amoral. His background is one of terrible abuse by his elders, which causes him to seek out death in battle because to him things can't get much worse. In his warped mind only one person every loved or respected him, but that person was exiled and he's been even more unstable ever since...