I'm the Queen in This Life

The Etruscan Kingdom is stained with blood when the king’s illegitimate son Cesare conspires with his fiancée Ariadne to usurp the throne from his half-brother Alfonso. Despite Ariadne’s devotion to the new king, her faith is shattered when she is betrayed by him and eventually murdered by her own sister, who wishes to be queen. To her surprise, Ariadne finds herself sent back in time to her 17-year-old self. As she navigates the perils and opportunities of palace intrigue, Ariadne must make the most of her guile and grit to ensure that her tragic future does not repeat itself. (Source: Mangamonster.net)