It is true that we have almost no way of knowing what the "untrained levies" brought by Xerxes with him on campaign felt or thought. Almost the only hint as to how 'colonial' troops expressed themselves is provided by letters from the Jewish garrison at Elephantine - and they date from long after 480. As a result, the historian has to put his hand up, and admit freely that some things lie beyond resurrection.

Bear in mind, though, that the troops flung into the jaws of Thermopylae on the third day of the assault were as foreign to Xerxes as the Spartans were. It was only once his 'anairya' levies had splintered the Greek spears to matchwood that his own countrymen, it appears, closed in for the kill. The motivation of the Persian aristocray is not, I hope, wholly opaque - and if you found it so, then I am sorry. Something to bear in mind for the paperback re-write, perhaps...