Cruel Palace - War of Flowers (2013)

Same setting, same characters. Both are about the Manchu invasions of Joseon. But unlike Three Musketeers, Cruel Palace is not an action drama, instead, it focuses more on the drama.

Same writer with interesting plots. Strong and ambitious female leads. Both female leads are scheming.

Both dramas deal with matters of royal and imperial harems. But the story in Cruel Palace isn't limited to the harem itself as in Legend Of Concubine Zhen Huan/Empresses In The Palace. Cruel Palace deals a lot more with politics. If you want a drama that deals with the harem but it is not entirely about that, maybe you should give a try to Cruel Palace.

Secret Door's King Yeong Jo and Cruel Palace - War Of Flowers' King Injo share a lot of similarities emotionally and in portrayal of characters. Both kings are portrayed very human and with lots of emotions, fears and scars and fragility. Both kings were enthroned by a coup. Also their relationships with their sons are very similar too, with very conservative fathers and less conservative sons. Also, I'd like to say Cruel Palace's Crown Princess is almost like a female version of Secret Door's Crown Prince Sado. Both dramas are very political and I feel that if you liked one you will like the other.

- Both are set during the same time period
- Cruel Palace is more focused on the court machinations behind Crown Prince Sohyun's death whereas My Dearest deals with the Qing invasion and its aftermath in the wider country

(I'm sorry if this sounds like a strange recommendation!!!)
Lee Duk Hwa plays similar (and adorable) characters in both of these dramas. Both characters have high political status, love children and aren't romantically loved. I personally pitied the characters. Even though he was so adorable he only suffered :(

The two are about beautiful women fighting for the king's attention, in the midst of a war. Besides, in the two, the heroine has temper, and gives up her first love by ambition/revenge

The two are about a famous royal concubine who was known for her beauty and her cruelty