King John affixed his seal to the Magna Carta at Runnymede in June of this year
[DOC] [TLE] Timeline of Magna Carta and its legacy - The British Library [PAR] John (r.1199-1216) is crowned King of England following the death of his older 
brother Richard I ... 10 June 1215 - Meeting at Runnymede begins ... known as 
the 'Articles of the Barons', to which the King's great seal was attached.