The Persian Boy follows the perspective of Bagoas, eunuch, courtesan (not sure if that's the right word, but I don't have a better one) to Darius III, and lover of the Alexander the Great, from childhood to Alexander's death.
First things first: It's a good book! I found the first person perspective grating at first, but it grew on me. Especially because Bagoas' perspective is interesting, and his subjectivity is what makes some of the events interesting to read about. (Even if I get frustrated that he is occasionally an awful judge of character, and I'll grumble about it even if it's justifiable in character.)
I've mentioned in previous posts that I knew about these books when I was 11 and in my full on Alexander the Great fan girl phase. (You know how some girls are horse girls? ...I mean, I was also a horse girl, but I was separately an Alexander the Great and Oscar Wilde girl. Read into that what you will) I really wanted these books when I was 11, and can I just say? I am so glad I read this one now, and not back then.

Yep, it's there in the beginning! I should have expected that! I'm not sure why I didn't!
In the beginning, Bagoas is enslaved, and shortly ends up a sex slave. When he's, like, 10. It's a thing that happens. The scenes aren't graphic, as such, but they are there, and yeah.
I still liked the book! I'd still recommend it, but with the hearty caveat of 'There's child sex slavery in here!'
It gets better once Bagoas meets up with Alexander-- but Bagoas is still 15. And while Alexander is aiming for 'free and uncoerced'; power differentials, and Bagoas' lack of other options are, like, a thing. (Like, from within Bagoas's perspective, he definitely wanted a sexual relationship with Alexander, and I am confident he was in love-- but from the outside it is quite creepy!)
It's a good book! I like the portrait it paints of Alexander! Bagoas is a charming narrator, who is at least usually reliable! I love how Renault gets into the heads of ancient people, and makes them believable without 'toning them down' for a modern audience! (Even if it does end up hellaciously creepy at times!) (Also, I love her portrayal of ancient religion, and I wish there was more in this book. Though there was plenty in Fire From Heaven, and I can understand her treading more lightly here, on account of Zoroastrianism being a bit more of a going concern than Hellenic paganism*)
So, good book, wouldn't recommend it to everyone.
Also, how weird is it to make fan content for a book that is arguably historical rpf? Does the two layers of separation from the actual people, and the actual people being very, very dead make it less weird? Asking for a friend.
*I'm aware that Hellenic Paganism is a thing-- but Mary Renault is working from the same sources as the Hellenic recons, and anything she doesn't know and has to make up is something the recons would also have to. That is not the case for Zoroastrianism.