The Magna Carta (originally known as the Charter of Liberties) of 1215, written in iron gall ink on parchment in medieval Latin, using standard abbreviations of the period, authenticated with the Great Seal of King John . The original wax seal was lost over the centuries . This document is held at the British Library and is identified as " British Library Co Original authors were the barons and King John of England . Uploaded by Earthsound .. Public domain.