The town linked to the Magna Carta ; in 1214 the barons of England are believed to have met in the Abbey Church and promised to force King John to accept the Charter of Liberties , the document which influenced the creation of the Magna Carta . The town is associated with Magna Carta . In 1214 the barons of England are believed to have met in the Abbey Church and sworn to force King John to accept the Charter of Liberties , the document which influenced the creation of the Magna Carta .