Westmark by Lloyd Alexander (The Westmark Trilogy, Book One)
Lloyd Alexander is best known for his Welsh-inspired high fantasy series, The Chronicles of Prydain (which I finally read last year and enjoyed). However, he wrote others novels set in historically influenced settings, including ancient India (The Iron Ring), ancient China (The Remarkable Journey of Prince Jen), and in the case of Westmark, the French Revolution. Its setting aside, Westmark includes themes that are common to Alexander’s stories, i.e., the protagonist is an idealistic young man who discovers that the world is a lot more complicated than he thought, and with the help of a cast of colorful characters, must fight evil while grappling with moral and ethical quandaries. This is far from weighty, preachy stuff, though. I read Westmark in just a few hours thanks to Alexander’s economical (though no less imaginative) writing and worldbuilding.