Thony Goes Astray! (in the Deep, Dark, and Dangerous Fairy Wood) - Kerridwen Mangala McNamara - Bog

Running away from home in order to save his kingdom was a Gallant sort of thing for a Crown Prince to do. A self-sacrificing sort of thing. Maybe even a brave sort of thing.
Definitely Proper Princely Behavior.
Right?
And there should be some pretty awesome adventures as Thony looks for his princess (whom he's too young to marry yet anyways, so there's plenty of time before any gross stuff like that).
And he's starting out in the Fairy Wood which has all sorts of amazing and scary stories about it. Other people have all sorts of adventures in there.
Unfortunately, Thony's adventure also involves an annoyingly superior stable-girl (his best friend, **sigh**), a grumpy unicorn, and an all-too-easily-freaked-out horse...