Bret Deveraux is the author of a blog that I've recently discovered and have been consuming quite avidly, A Collection of Unmitigated Pedantry. The name won't tell you much, unfortunately, but I'm here to convince you it's worth your time before you click away.
Bret writes blog posts, often in series, going into detail as to historical reality (or lack thereof) of common tropes (religion in the middle ages), ancient societies, and even fictional stories, covering economics, military organization (strategy and logistics and tactics), social structure, an much more.
If you ever wanted to read about how war in Lord of the Rings worked, what lies behind the 300 Spartans, or even why Dune might be misleading in ways that have echoed through millenia, look no further.
For a table of contents of sorts, Resources for Teachers is a good place to start.
Happy reading!