There is no evidence to suggest that a single original Magna Carta was written out and ceremonially sealed at Runnymede in June 1215.
Instead, scribes in the royal chancery subsequently wrote up many copies of the charter, providing legal evidence of the settlement which had already been agreed.
Each of the many copies produced by the scribes was 'an original Magna Carta'. The issue of 13 is recorded, but many more were probably produced since the king had ordered a national proclamation of the charter. Only four now survive, two in the British Library, one in Lincoln and one in Salisbury.
The scribes wrote Magna Carta with quill pens on sheets of parchment made from treated sheepskin, the usual writing surface of the period. Because parchment was very expensive, the scribes used a small script and they abbreviated the Latin text to save space. Like other royal charters, Magna Carta was authenticated with the Great Seal, not the king's signature.