The time is the Persian Wars, about 20 years before the date of my first book. Xerxes, the Great King of Persia, has decided to subjugate Greece, and to do so he's assembled the largest land army the world has yet seen. A very hungry army which is eating everything in its path.

The massive force arrives at a city in Asia Minor called Celaenae, in what is now modern Turkey. They are still inside the Persian Empire, but the locals are not exactly thrilled to have their King pop in with an army that they have to feed.

I'm going to let Herodotus take over, courtesy of Penguin Classics:

Here at Celaenae a Lydian named Pythius, the son of Atys, was awaiting Xerxes, and on his arrival entertained him and the whole army with most lavish hospitality, and promised besides to furnish money for the expenses of the war. The mention of money caused Xerxes to ask the Persians present who Pythius was, and if he was really rich enough to make such an offer. "My Lord," was the answer, "it was the man who gave your father Darius the golden plane-tree and the golden vine; and still, so far as we know, he is the wealthiest man in the world, after yourself."

Pythius, son of Atys, was probably a grandson of Croesus. Yes, that's Croesus of "rich as Croesus" fame. Croesus is known to have had a son called Atys - the same name as Pythius' father - and the dates check out. No wonder Pythius is fabulously wealthy.

Xerxes, overjoyed to find one of his subjects who is not only pleased to see him, but wants to help, asks how much money Pythius has. Pythius replies:

I possess 2,000 talents of silver, and 3,993,000 gold Darics. This it is my intention to give to you; I can live quite comfortably myself on my slaves and the produce of my estates.

This is a vast amount of precious metal. Even by modern standards, Pythius would be a billionaire. Xerxes, to put it mildly, is pleased:

My Lydian friend...as a reward for your generosity, I make you my guest-friend and, in addition, I will give you from my own coffers the 7,000 gold Darics which are needed to make your fortune up to the round sum of 4,000,000. Continue, then, to possess what you have acquired; and have the wisdom to remain always the man you have proved yourself today. You will never regret it, now or hereafter.

How to win friends and influence people indeed! Pythius could have been almost bankrupted, but instead finds himself guest-friend of the Great King, which means he has the ear and good will of his absolute monarch.

So far so good. The only bad news for Pythius is he has 5 sons, and Xerxes takes all 5 of them into the army, as he has every able-bodied man in sight. Pythius is worried. He goes to Xerxes and says:

My Lord, I have 5 sons, and it happens that every one of them is serving in your army in your campaign against Greece. I am an old man, Sire, and I beg you in pity to release from service one of my sons - the eldest - to take care of me and my property. Take the other 4, and may you return with your purpose accomplished.

Sounds reasonable enough for a guest-friend to ask, a man who's offered to fund the entire war. Right?

Xerxes says:

You miserable fellow! Have you the face to mention your son, when I, in person, am marching to the war against Greece with my sons and brothers and kinsmen and friend - you, my slave, whose duty it was to come with me, with every member of your house?

Uh oh. Things are not looking good for poor Pythius. Xerxes refers to Pythius as a slave because, under the Persian system, every man was considered a slave of the Great King. Xerxes goes on in this unpleasant vein for some time. Pythius must have thought he was about to be executed by his angry king before Xerxes says:

Yourself and 4 of your sons are saved by the entertainment you gave me...

Saved! Pythius' habit of sucking up to absolute monarchs pays off.

But wait! Xerxes said 4 sons were saved, not 5...

...but you shall pay with the life of the 5th, whom you cling to most.

Xerxes at once gave orders that the men to whom such duties fell should find Pythius' eldest son and cut him in half, and put the two halves one on each side of the road, for the army to march out between them.

The order was performed, and now between the halves of the young man's body the advance of the army began.

This sort of casual brutality might not have happened every day, but it was normal and acceptable in the Persian social order, the same society which used a rather painful execution method.

Note a clear implication of this tale is that among Xerxes' staff were men whose job description included, "cutting people in half."

Xerxes does not get good press from the Greeks, for obvious reasons. He fares just as badly in modern hands. Think of the movie 300. The evil bad guy commander in that is the same Xerxes who just offed a guy in this little story because his father asked a favor.