Magna Carta
The "Cotton MS. Augustus II." exemplification of the Magna Carta. Dated 1215.
One of only four surviving official copies of the text.
This version was part of a larger collection of antiques and curiosities curated by Robert Bruce Cotton beginning in the late 16th Century under the "Augustus Wing" of his library, hence the name.
First drafted in 1215 by then Archbishop of Canterbury, Cardinal Stephen Langton, agreed to by King John in that same year, annulled by Pope Innocent II which led to the Baron's War and later reissued under John's son Henry III one year later with a less aggressive stance towards the royalty it concerned and whose power it attempted to limit. It was issued numerous times over the course of his reign before it became English law upon which it was renewed by every monarch until parliament's influence had grown sufficiently to diminish its practical importance.