The main protagonist is Shen Tai, the second son of a recently deceased General - his elder brother (Shen Liu) is a bureaucrat in the capital, he himself was about to take the exams to become a bureaucrat when his father died. During the traditional 2 year mourning period Shen Tai breaks with tradition by going to the north of the country & starts to bury the one hundred thousand dead in the battle which lead to his father's most famous victory - to show honour to his father. The story opens with him being given a gift (of 250 horses - an overwhelmingly rich gift) by the Kitan bride of the ruler of the defeated country, in recognition of his labours. And a friend arrives to bring him urgent news.
And from there, intrigue and politics ensue partly hidden by a veneer of courtly manners. The narrative has a great sense of how the little personal things are important to history - if Shen Tai hadn't been in love with the Prime Minister (Wen Zhou)'s new concubine (Spring Rain), then there would have been no animosity between them. If Wen Zhou hadn't been so keen on triumphing over a political rival (An Li), then he wouldn't've backed An Li into a corner and there would've been no rebellion. Events in Shen Tai's past set in train the events that save his sister from her arranged marriage (and change the ruler of another kingdom).
The machinations of court and the protocol & honour-driven society are well drawn, so much so that it felt like there was always more going on under the surface than I really had a handle on. I spent a fair chunk of the book half-wishing that one of the characters would tell me what was going on, just so I could check I'd figured it all out. But then towards the end there was a bit of a tone shift and the narrative started to include paragraphs that started with things like "At least three historians of a later dynasty, ..." which explained bits & pieces and I wasn't quite sure if I liked having got what I'd wished for ;) I was also not entirely convinced by the wrapping up of all the loose ends - it makes sense from the perspective of this being a history (so we know what happened to everyone), but at the start there isn't that sense of distance from the events and characters. And I'm not sure the shift worked for me.
It's a bit of a hard book to categorise - it's not quite a historical novel, because it's not set in a real place & time. It's not quite alternate history, because it's not extrapolating forward from a change. I suppose it could be called fantasy, but I feel like it's too close to the real world to quite fit in that genre (it's got the wrong flavour to it).
I did enjoy the book overall, I'm just not quite sure I worked out all of what was going on.