Magna Carta. This document, the Great Charter of English liberties, was first issued by King John I at Runnymede on 15 June 1215. It established the principle that the King was subject to the law and limited the power he had over his barons. This document, held at the British Library, is one of four surviving official productions of the 1215 document. These versions of the charter, known as exemplifications or engrossments, are official records that were sent out by the royal record office to courts across England. The document is written on parchment in medieval Latin.