Histories
Herodotus
Herodotus. Godley, Alfred Denis, translator. Cambridge, MA; London: Harvard University Press; William Heinemann, Ltd., 1920-1925 (printing).
Xerxes and his barbarians attacked, but Leonidas and his Hellenes, knowing they were going to their deaths, advanced now much farther than before into the wider part of the pass. In all the previous days they had sallied out into the narrow way and fought there, guarding the defensive wall.
Now, however, they joined battle outside the narrows and many of the barbarians fell, for the leaders of the companies beat everyone with whips from behind, urging them ever forward. Many of them were pushed into the sea and drowned; far more were trampled alive by each other, with no regard for who perished.
Since the Hellenes knew that they must die at the hands of those who had come around the mountain, they displayed the greatest strength they had against the barbarians, fighting recklessly and desperately.