Okay, I know some of you may be like "Whaa?" but hear me out on this one.
Both are about girls stuck in a political battle between kings.
Both have two (or more) love interests fighting over them.
Both have feelings for two characters.
Both are historical (duh).
And they both have main leads who are humanly flawed and aren't always the best people - which is understandable in this era and time.