Pride of place amongst the copies goes to that contained within the letter issued by Archbishop Langton, the archbishop of Dublin, other English bishops, and Master Pandulf, the papal ‘familiaris’, as testimony to the 1215 Charter’s authentic text. The letter (of which there may have been several engrossments) was probably issued at Runnymede itself. No engrossment of the letter survives, but it was copied in 1323 into an exchequer volume known as ‘The Red Book of the Exchequer’ almost certainly from the original text then residing in the exchequer’s treasury.1 The copy in the ‘Red Book’ has never been published but it was collated with the Lincoln and two British Library engrossments in Statutes of the Realm, published in 1810. The main variations with these three originals, as also with the Salisbury engrossment, are also noted in the footnotes to the Lincoln text published in my own Magna Carta, pp.36-69.2 The collation shows that the Red Book text has some small errors, presumably made by the copyist in 1323, but in all important respects coincides with the texts found in the four surviving engrossments, just as those four agree with each other.
TNA E 162/ 2, fos.ccxxxiiii-ccxxxvi verso. See A. J. Collins, ‘The Documents of the Great Charter of 1215’, Proceedings of the British Academy, xxxiv (1948), pp.248-54.
D. A. Carpenter, Magna Carta (Penguin Classics, 2015)