Empress of Another World(2016)

Crossing over into another world and time after a freak accident, Korean highschool girl Sabina is taken in by a duke of the Crentia kingdom only to soon be offered up to the ugly old emperor as a concubine. When the king is killed by a mysterious assassin, Sabina must face the poisonous circle of other candidates in a battle for the royal seat. Can she attract the loyalty and affection of the men and women she needs on her side to survive?

(Source: Tappytoon)