What is the name of the English document signed in 1215 that limited the king’s power?

The story behind the answer

Signed by King John at Runnymede in 1215, this charter compelled the monarch to obey the law. It curbed arbitrary taxation and imprisonment, guaranteeing baronial consent for new taxes and protections like due process and trial by peers. The core idea: even the king is not above the law.

Though intended to resolve a crisis with rebellious barons, it was reissued and later celebrated as a cornerstone of constitutional government, inspiring legal traditions in England and beyond, including American constitutional thought. The other options belong to different eras: the Petition of Right (1628) checked Charles I; the English Bill of Rights (1689) followed the Glorious Revolution; the Charter of Liberties (1100) was Henry I’s earlier promise, less enforceable and narrower in scope.