My hat is off to you for tackling such a daunting subject.

This story is set in Goguryeo, a time when the status of women in Korea was much higher than in the rest of Asia or even the rest of the world. South of Goguryeo was Silla, which during its history actually had three ruling Queens (see 2009's THE GREAT QUEEN SEONDEOK for the story of the greatest of these queens). Whatever the rules were that were in effect then have to have been different from the Neo-Confucian nonsense imported into Korea during the Joseon and almost certainly also different from the Buddhist dominated society that prevailed during the Goryeo dynasty. Further- Goguryeo at its greatest extent was a big country, actually a true empire the majority of whose subjects were not Korean. This is why it is quite possible that a much different set of principles prevailed there.

It's based on true story. She indeed married her brother-in-law Sansang, circa 197 AD, after her husband Gogukcheon of Goguryeo died. Whether the story truly played out as they show in the drama is tbd.
Courtesy: Beanie @kiara

Ooh yikes, sleeping with your parents' sex partners, that seems like a bad idea.

It also happens in the Bible, but it is double-plus ungood when it does.

I'm putting together a historical summary of the Three Kingdoms era, and I'll tag you when I'm done.

If you're interested in learning about the founding myth of Goguryeo, I recommend watching JUMONG @viki. It has numerous episodes, but it provides a good understanding of the written history. Goguryeo consisted of multiple tribes with similar customs and traditions, which were distinct from those of later Joseon, with which we are more familiar.

Based on pics you provided I wonder if production deliberately opted for different style of hair crown because "jougwan" looks a bit silly... Then again, KINGDOM had all kind of silly feathered gats possible, but it didn't distract from horrors of plot and foreign audience actually loved them for unique visuals.

Anyway, they knew what they're doing - hopefully they're also ready for consequences, unlike KBS with JE. Latter, irc, was doomed once all sponsors ditched the show so there was no financial point to air it anymore. I assume paid-to-access streaming platform wouldn't have such problem?

Indeed, very important to both. At its height much more of Goguryeo lay in China (plus the Russian maritime province) than in Korea. So Goguryeo is just as much about China as it is about Korea.

Meanwhile QUEEN WOO also covers the time of the fall of the Han Dynasty which took place while she was Queen of Goguryeo, leading into the Three Kingdoms Era of Chinese history. This is quite literally the most 'romantic' period of Chinese history so the Chinese would be particularly sensitive about how it is portrayed.

I enjoy watching dramas for various reasons. It's always fun to find friends who share my interest in the dramas I like, and learning from each other is enjoyable. I especially appreciate their "honest" opinions and engaging discussions. I find the ancient history of Korea, China, and Japan fascinating! I love reading history books, watching documentaries, and sometimes keeping up with current politics. As a history enthusiast, I am drawn to historical dramas based on documented records. These are rarely produced nowadays, but they are worth my time.

As always, a very good point here.

This is exactly right--as @elinor says, when it comes to ancient history of any country, even in "well" documented practices, the documentation is limited, often to an elite-produced single source, scraps of a poetic legend, or an archeological dig, and they themselves are open to wide variation in contemporary interpretation. Plus the questions these consumers of historical drama are arguing about would be unanswerable anyway. Who knows the origins of certain practices? There's no single "inventor" of food or fashion, and practices are constantly changing to adapt to people's tastes.

Beyond nationalist, hyper patriot ideology, I think the obsession with historical authenticity among some watchers of sageuks is itself a matter of taste. For them, the idea that it is "accurate" adds a certain gravitas to the production, which increases their viewing pleasure. Its similar to going to an immigrant restaurant and enjoying the food more because its "authentic." I myself have never been too hung up on historical accuracy in historially based shows and movies, but I recognize that for some its subjectively important in their appreciation.

On the other hand, I do feel these geopolitical quarrels are historical nonsense. Alarming in the tension they reveal, but nonsense nonetheless.