This year of 2015 will see many Magna Carta anniversary events along the River Thames.
The site of the sealing of the charter is of course Runnymede.
But the barons had been plotting and negotiating with King John at The Temple in the City of London where there are anniversary events.
Another focus for the 800th anniversary year is Barnes wehre Archbishop Langton stopped off on his way back from Runnymede to consecrate the parish church.
On the actual anniversary day of Magna Carta there will be a service at St Mary’s Barnes where the preacher is Archbishop’s Langton’s successor Rowan Williams.
But has Barnes chosen the right day? It seems that Archbishop Langton, who secured the King’s agreement to the charter on Trinity Monday 15 June 1215, probably stayed another week as post agreement negotiations continued until Friday when the barons renewed their homage to the King.
So the consecration at Barnes could have been on Saturday 20 June with the Archbishop reaching his home in Lambeth in the evening.
At Barnes the anniversary year of lectures and other events begins with a visit by the Bishop of Southwark on 1 February.
In June a three day walk is planned from Runnymede to Barnes. A few days earlier villagers from Odiham in Hampshire, where King John set out for Runnymede on Wednesday 10 June 1215, will be walking to the Magna Carta site by the Thames.