King John of England and a group of rebel barons agreed on the text of Magna Carta, an influential charter of rights.

John, King of England
John was King of England from 1199 until his death in 1216. He lost the Duchy of Normandy and most of his other French lands to King Philip II of France, resulting in the collapse of the Angevin Empire and contributing to the subsequent growth in power of the French Capetian dynasty during the 13th century. The baronial revolt at the end of John's reign led to the sealing of Magna Carta, a document considered a foundational milestone in English and later British constitutional history.
Magna Carta
Magna Carta, sometimes spelled Magna Charta, is a royal charter of rights agreed to by King John of England at Runnymede, near Windsor, on 15 June 1215. First drafted by the Archbishop of Canterbury, Cardinal Stephen Langton, to make peace between the unpopular king and a group of rebel barons who demanded that the King confirm the Charter of Liberties, it promised the protection of church rights, protection for the barons from illegal imprisonment, access to swift and impartial justice, and limitations on feudal payments to the Crown, to be implemented through a council of 25 barons. Neither side stood by their commitments, and the charter was annulled by Pope Innocent III, leading to the First Barons' War.
Bill of rights
A bill of rights, sometimes called a declaration of rights or a charter of rights, is a list of the most important rights to the citizens of a country. The purpose is to protect those rights against infringement from public officials and private citizens.