West of January by Dave Duncan. "Sci-fi". After rereading A Man of His Word series I was unhappy. A let down from leaving that world I suppose. Instead of continuing on tried something different. Liked it a lot. The beginning had a more serious tone than usual Duncan. Was really impressed. But eventually, despite the awful things that happened to him, it ended up feeling like his usual character who wasn't really affected by things somehow. Such as is normally the case in fantasy fiction/sci-fi. But then, it's fine line to walk when you're putting someone through such things while hoping the reader will keep turning the pages.
Anyway, starts with the Herdman who send the boys off on their own when they get armpit hair. They usually die. Adult male herdman have a ton of wives and except for rare traders/trades have no interaction with other herdmen except to fight to the death. Knoble leaves their with an "Angel". Then stays with the Seafolk for a while. Then a slave to the miners. Then sold to Traders. Then sold to a Spinster. Then saved by Angels. Stays with them quite a while. And then goes back to Herders and becomes their king while changing their way of life. Uses his power to destroy the slavery of the miners and that's that.