Tada no Murabito no Boku ga, Sanbyakunen Mae no Boukun Ouji ni Tensei shite shimaimashita ~Zense no Chishiki de Ansatsu Flag wo Kaihi shite, Odayaka ni Ikinokorimasu!~

Prince Rudolf gained knowledge of the future 300 years from now during a near-death experience. He uses his wits to change the future in which he will be assassinated as a tyrant prince.
Meanwhile, discrepancies between the story passed down to posterity and reality gradually emerge...