In Britain under the monarchy, the development of law is inseparable from kingship and history. British law in the Middle Ages experienced a period of rapid development, it included the Early Germanic law, Canon law, Roman law, Common law .Their main ideas are all condensed together to promote the formation of a new concept of the law. Different laws reflect different cultures and histories, and will also change with the progress of history. There are many famous scholars studying in law in this medieval period, such as the famous judge, Henry Bracton. He writes a lot about the law in the middle ages and also how it is developed and why it becomes the law now we see. However, In medieval England, due to the beginning of royal rule, many different legal systems were formed, such as the Canon law...During the transition from the formation of the law in the Middle Ages to the modern law, the ideology continued to merge and progress. In short, the history of royal power is closely related to the development of law.