I should have started reading the newest series by Elizabeth Moon much sooner. In the late 80's Moon wrote a trilogy called The Deed of Paksenarrion. In a fantasy world, a sheep-farmer's daughter, a big sturdy girl, joins the local Duke's military to avoid an unwanted marriage. She rises to become a paladin and to see that lord chosen as a kingdom's heir. I liked that trilogy quite a bit. I've even held onto my yellowing paperbacks all these years. In the decades since, Moon has written a number of military science fiction novels that just didn't catch my interest, though they've been popular and well received. Recently Moon has gone back to the world of The Deed of Paksenarrion with the start of a new trilogy.
You don't need to read the first series to enjoy Oath of Fealty, the first in this new trilogy. It has been twenty plus years since I read the original books and I had no trouble falling into this new story. Paks, the heroine of the first trilogy is only a secondary character in this trilogy.
In Oath of Fealty, after the duke, Kieri Phelan, is discovered to be the heir to a neighboring kingdom, he leaves his former holding under the care of his captains, one of whom will be named the new lord in his place. The kingdom Kieri is leaving is in turmoil after the assassination of the king, leaving an untried young prince about to be crowned. To add further to the machinations, the assassin of the young prince's father was one of his other dukes. Now the crown prince must question the traitor's entire family to find how far their service to an evil god and blood magic has spread. That leaves only one reliable person to whom the lands might be entrusted: an aging captain of Kieri's who was cast out of the family as a girl for refusing to practice blood magic. I really need to get my hands on book two, Kings of the North, in short order because the end of Oath of Fealty left me wanting more.