It sounds like two best "gal pals" that were taken away from each other and one was a rebellious princess while the other a warrior princess whose kingdom was betrayed disguised as a head maid and was accused for being a witch because she had many husbands that were actually her allies in disguise and seducing the emperor when instead he was the one who tried to force her to become his concubine and the princess was forced to marry an old duke by the empress in order to hide her love affair with the maid and she cries in the maid's arms. The maid was killed at the princess's engagement day after being framed by the empress for good luck. While everyone was celebrating the witch's death in the princess's wedding banquet she jumps out the balcony with a knife in her chest as since her love had died there was no reason for her to live and she didn't wanted to marry the old duke, only to realise the maid hadn't died and was preparing for them both to run away but she still smiles as her love had survived and she could her kiss love one last time. Later the maid destroys the empire with the help of her people that had planned a rebellion and commits suicide near her love's grave saying that she finally avenged her. Centuries later the historians find their handwritten letters and songs of love along with the princess's grave that had been near the maid now empress's grave while the princess's grave read the beloved one of the empress and are still saying they were "good friends".