Which Medieval Romance Novels Have Anime Adaptations?

A witch who has lived for thousands of years has grown bored with her own life and decided to leave it. Since she is an immortal, her soul cannot leave the world. However, what she can do is transfer her soul to another body. By a stroke of luck, she happens to enter the body of a princess. She was considered a miracle because when the Empress gave birth to her, the princess instantly died, along with the Empress. What the witch didn't know was that she has entered such a predicament. She has to endure the love of the cruel Emperor and possessiveness of the crazy twin princes! What will her life be at the hands of such a loving family? In addition, it seems that this body contains mana that was lost in the royal family centuries ago!

The Demon King’s Bride The entire kingdom fears him. With white hair, piercing blue eyes, and a heart sealed by cruelty, King Edrion is known as the Demon King—a ruler who accepts betrothed brides… only to turn them into concubines and discard them without mercy. When a young noble lady is promised to the king, her fate seems sealed. But she refuses to give up her freedom—or the man she secretly loves: a guard from her own household. Desperate, they devise an unthinkable plan—to have a poor girl, identical to the noble, take her place as the royal bride. The girl agrees to assume a life that is not hers, believing she will become nothing more than another forgotten concubine in the shadow of the throne. What no one expected… is that the king would choose her. Now destined to become queen to the most feared man in the kingdom, trapped in a lie that could cost her life, she must survive the court, a forbidden desire, and a king who was never meant to look at her the way he does. Because the Demon King does not love. But when he chooses… he neither forgives nor lets go.

Life seems colorful and fun for Princess Adelia until someone she loves gets taken a way from her. Adrian is a knight that has been assigned to protect the princess after an encounter that nearly ttook her life. His stoic and serious expression coupled with his agile build and sarcastic persona makes him the perfect man for the job. He's drawn to the calm and beautiful princess. But he knows her attention is on something else. Adelia is determined to find who did this to her family. she knows she can't do this alone, so she asks for help. Who's a better help than her own guard? The two are faced with many obstacles, but never did they expect her bethrothal to a far away prince. Adelia thinks she's faced enough betrayal. Little does she know the pain has just began. There would be love, bloodshed, betrayal pain. At the end, there would be victory.

The day my elder sister stole my fiancé from me, I did not fight back. Instead, I slipped past the maid guarding me and went straight to find my father. “She can have my fiancé. I’m marrying the Regent!” My father stared at me in shock. Everyone knew the Regent was in charge, but rumors said he could not father a child and had a nasty temper. What they did not know was that I was born under heaven’s favor—blessed with the gift of life itself. In my previous life, that blessing became my curse. My elder sister and stepmother smeared my name, claiming that my curves and easy fortune meant I had been defiled before marriage. My fiancé was disgusted and turned away from me. That was when my sister seized the chance to take my place. Even on her wedding day, my sister was not at ease. She had me dragged away like a lowly servant and sent to a brothel, ordering the madam to torture me. While I lay dying in the dark, she lived in the light, bearing children with my former fiancé and enjoying a lifetime of happiness that should have been mine. Now that I had been given another life, I refused to bow to fate again. She might have stolen my fiancé, but she could never take the blessing I was born with.

Serra is a normal senior high school student who works really hard every night and weekend to pay off her parents' debts from loan sharks. But when she couldn't keep up with payments anymore, she decided to end her life. Surprisingly, she woke up in a different light-- in another world. What's more shocking was when she is addressed by one of the people as the demon king's bride.

A story of a princess from a native tribe who chose to end the war by giving her hand for a marriage to a prince, an enemy of the tribe, who vowed to destroy her the moment she will set foot his kingdom...