Magna Carta, or Magna Charta (Latin, “great charter”), major British constitutional charter forced on King John I by a baronial alliance at Runnymede (1215). A reaction to John's heavy taxation and his exclusion of the barons from government, the charter was designed to prevent royal restriction of baronial privilege and feudal rights and to safeguard church and municipal customs. Altered forms of the decree were issued on John's death in 1216 and again in 1217 and 1225. Now generally recognized as a reactionary measure to guarantee feudal rights, it has, in the past, been interpreted to suggest and defend such civil rights as habeas corpus and jury trial. It paved the way for constitutional monarchy by implicitly recognizing that a king may be bound by laws enforceable by his subjects.