I had good memories of reading this as a child, but rereading now, boy, it's definitely a children's book. Super short, super simple and things just happen without a ton of explanation or detail. And Elionwy's spoiled brattiness, which was irritating to start with, hasn't aged well.

In short: it's the story of Taran, an assistant pig keeper in a small kingdom in a place very much like Wales who is sucked up into mythic conflicts involving Arawn, the Big Bad who creates a zombie army to rule the world by cooking corpses in the Black Cauldron (see book 2), and an evil witch who is trying to take his place. Also heroic Princes, wise war heroes and wizards, and various creatures of myth and legend.

Recommended for kids maybe 10 at most, pretty simple going for anyone older than that.