One of a series of five historical novels set in antiquity that de Camp wrote, this one is derived from an odd little piece of archaeology: a set of friezes showing "tributary kings" bringing gifts to the Persian emperor Xerxes, including three *Pygmies* bringing elephant tusks and an Okapi. (Side note: this frieze was discovered before the OKAPI was by Europeans, so for about 40 years archaeologists called the animal shown a "fanciful, short-necked giraffe".) So de Camp asks "what the hell were pygmies and an okapi doing in Persepolis" and sets out to find out.
De Camp was a history and archaeology nerd of the highest order and it shows in his writing, with lots of fascinating details, historical character and a great afterword about what went into the book. However, his normal writing style -- when he wasn't writing Robert E Howard pastiche, for example -- was towards the whimsical and tongue and cheek and that weaves through this book -- not always to its betterment. At times, it makes for great little asides, at other times -- almost anytime we are dealing with Xerxes and his "wizard" Ostanes, for example, like you are watching the bumbling villains of an old Abbot & Costello movie. It's an uneven tone that may have worked better in another era, which is why I am giving it 4 stars and not 3.