Throughout the winter of 1214–15, means were sought to restrain the king and to preserve the peace. At some point, perhaps as early as July 1213, the Coronation Charter of Henry I had been brought into debate. Issued as long ago as 1100, this charter imposed limitations on the king’s power to tax or compel his barons, including provisions on the Church, over widows and orphans, and in relation to testamentary and marriage rights.
The ‘Unknown’ Charter begins merely as a copy of Henry I’s Coronation Charter. It then lists a series of additional clauses, beginning with the statement, ‘King John concedes that he will arrest no man without judgment nor accept any payment for justice nor commit any unjust act.’ In embryo, this supplies our first evidence for what was to develop into clauses 39 and 40 of Magna Carta. In the ‘Unknown’ Charter these clauses are followed by others set out as bargaining points between King and barons. Most, but not all, of these clauses subsequently found a place in Magna Carta. The ‘Unknown’ Charter, for example, attempted to limit the tax paid on knight service, known as scutage, and to ensure that the King could not summon his barons to serve in France, save in Normandy or Brittany. Neither of these points was adopted at Runnymede.
The document is named the ‘Unknown’ Charter because it was rediscovered in the French national archives in 1863 and not publicised in England until the 1890s, long after most of the other significant Magna Carta texts had entered scholarly debate. It perhaps travelled to France in 1215 or shortly afterwards, in the baggage of an English rebel, possibly with Master Simon Langton (d. 1248), the Archbishop of Canterbury’s brother, a leading supporter of the barons and himself an employee of the French royal court.