After seeing only a few episodes I was hooked and thrilled that this drama had 51 episodes, so don't be discouraged by the large number of them. I could hardly stop watching to take breaks, what with the fascinating storyline and the terrific acting of the leading players, Ji-Won Ha, Jin-Mo Ju, and Chang-Wook Ji. Apparently, this has a true basis in Korean history that connects it to the Mongolian Dynasty, the Yuan, of the 13th-14th centuries. it's not important that I give plot information since several others have already done that, but I must say that the love triangle was gripping and suspenseful. Ji-Won Ha portrayed an extraordinary woman of strength and intelligence while serving the rather feckless emperor, a difficult role handled beautifully by Chang-work Ji. But my attention was completely riveted when the King of Koryo (Korea) depicted by Jin-Mo Ju came on the scene. Wow, what a face, and that resonant voice, altogether his character bringing a dignity and commanding presence to the screen..There is a certain amount of brutality as is expected in that era, but everything seemed well designed for a sense of authenticity. I'm now rewatching the entire series again and finding it as enriching as the first time.