The court of shadows (Vampyria #1)

A fiery heroine seeks vengeance against a royal court of deadly vampires in this epic alternate history set in lavish Versailles. Louis XIV transformed from the Sun King into the King of Shadows when he embraced immortality and became the world's first vampire. For the last three centuries, he has been ruling the kingdom from the decadent Court of Shadows in Versailles, demanding the blood of his subjects to sate his nobles' thirst and maintain their loyalty. In the heart of rural France, commoner Jeanne Froidelac witnesses the king's soldiers murder her family and learns of her parents' role in a brewing rebellion involving the forbidden secrets of alchemy. To seek her revenge, Jeanne disguises herself as an aristocrat and enrolls in a prestigious school for aspiring courtiers. She soon finds herself at the doors of the palace of Versailles. But Jeanne, of course, is no aristocrat. She dreams not of court but of blood. The blood of a king. Translated from french by Francoise Bui, Original edition: La cour des ténébres (2020)