Thought I'd better get on and read this, as I have a copy of Half the World (the next book in the trilogy) from the library and it's got to go back by this coming Friday...
On finishing this book, I was kind of torn between giving it 3 or 4 stars, but the fact that I read it through in pretty much one sitting pushed me towards the latter - I wanted to know how it would all turn out, even though I already knew that the main character survived whatever the author was going to throw at him, since he's in Half the World. Because I'd seen a blurb for that book, I knew there was going to be at least one plot twist at the end in order to set that up, but didn't quite get what was going to happen in advance, so kudos to the author for enough subtlety not to be guessable out of the gate.
So, anyway, on to Half a King itself. Our main character is Prince Yarvi, born with a misshapen hand in a world that values physical prowess above all else - the setting is loosely Viking, with lots of raiding and sailing about going on. There's some very nice world-building going on despite the stock background, especially the clear valuing of knowledge as a female preserve, and when we first meet him Yarvi is training to become a royal advisor. Shortly before he's due to take his final test and therefore separate himself from his family, his father and brother are killed, leaving Yarvi as king.
He is encouraged by his uncle Odem to lead a raid into a neighbouring country, despite his lack of military experience and overall fighting skills, where his uncle turns out to have more sinister plans. Yarvi is only half a king in Odem's mind, so therefore he's doing everyone a favour by taking over. Escaping Odem's attempt on his life, Yarvi ends up being captured then, deciding he'd better not tell anyone who he really is since everyone he knows wants him dead anyway, ends up sold as a slave to a galley. There, naturally, he meets the folks who will eventually end up escaping alongside him and who will play a significant role in his quest to return home and deal with his treacherous uncle.
If anyone's been reading epic fantasy for a while, none of the above is going to be much of a surprise in terms of plot and though this has been marketed as Young Adult it still probably has moments that wouldn't suit the most squeamish of readers. The choice of settings for most of the plot mean comparatively limited opportunities for female characters, although those who do make an appearance are solidly-written. The next book, Half the World, seems to have more central female characters as well as a little more diversity among them - it's set fairly soon after Half a King, so Yarvi is still quite young but will hopefully resist any YA love triangles or similar nonsense!