The original 1215 text of Magna Carta was written in Latin.
King John sealed the charter at Runnymede in June 1215 after negotiations with rebellious barons. Latin was the standard written language of administration, law, and scholarship in medieval England, so the document was composed in that language rather than in the everyday speech of most inhabitants.
Magna Carta was not originally a modern democratic constitution. It chiefly limited royal authority and confirmed certain rights and feudal arrangements, especially for the barons. Only a small number of its clauses remain legally operative in England and Wales today.
The charter was later reissued several times. The 1215 version is the famous first issue, while the 1216, 1217, and 1225 reissues altered or omitted material. Its Latin wording helped preserve it as a legal and historical source.